Monique Delos

Influence of the route of administration and the chemical form (MnCl2, MnO2) on the absorption and cerebral distribution of manganese in rats.

Abstract  The absorption and cerebral distribution of manganese (Mn) have been studied with respect to the route of administration and the chemical form of the Mn compound. Different groups of adult male rats received either MnCl2 · 4H2O or MnO2 once a week for 4 weeks at a dose of 24.3 mg Mn/kg body wt. (b.w.) by oral gavage (g.) or 1.22 mg Mn/kg b.w. by intraperitoneal injection (i.p.) or intratracheal instillation (i.t.). Control rats were treated with 0.9% saline. Four days after the last administration the rats were killed and the concentration of Mn measured in blood, hepatic and cerebral tissues (cortex, cerebellum, and striatum). The liver Mn concentration was not affected by the treatments whatever the chemical form or the route of administration of the Mn compound. Administration of MnCl2 by g., i.p., and i.t. routes produced equivalent steady-state blood Mn concentrations (about 1000 ng Mn/100 ml), representing increases of 68, 59, and 68% compared with controls, respectively. Mn concentrations were significantly increased in the cortex but to a lesser extent (g., 22%; i.p., 36%; i.t., 48%) and were higher in the cerebellum after i.p. and i.t. administrations than after oral gavage. Rats treated i.t. with MnCl2 showed an elective increase of the striatal Mn concentration (205%). In contrast, MnO2 given orally did not significantly increase blood and cerebral tissue Mn concentrations; the low bioavailability is most likely due to the lack of intestinal resorption. Administration of MnO2 i.p. and i.t., however, led to significant increases of Mn concentrations in blood and cerebral tissues. These increments were not significantly different from those measured after MnCl2 administration, except for striatal Mn after i.t. which was markedly less (48%) after MnO2 administration. A comparison of the blood Mn kinetics immediately after g. and i.t. treatment with MnCl2 or MnO2 indicated that the higher elevation of blood Mn concentration ( > 2000 ng Mn/100 ml) after i.t. administration of MnCl2 could account for the elective uptake of Mn in the striatum observed in repeated dosing experiments. It is concluded that the modulation of Mn distribution in brain regions according to the route of administration and the chemical form of the Mn compound may be explained on the basis of different blood Mn kinetics and regional anatomic specificities of the striatal region.

Azithromycin reduces spontaneous and induced inflammation in ΔF508 cystic fibrosis mice

BackgroundInflammation plays a critical role in lung disease development and progression in cystic fibrosis. Azithromycin is used for the treatment of cystic fibrosis lung disease, although its mechanisms of action are poorly understood. We tested the hypothesis that azithromycin modulates lung inflammation in cystic fibrosis mice.MethodsWe monitored cellular and molecular inflammatory markers in lungs of cystic fibrosis mutant mice homozygous for the ΔF508 mutation and their littermate controls, either in baseline conditions or after induction of acute inflammation by intratracheal instillation of lipopolysaccharide from Pseudomonas aeruginosa, which would be independent of interactions of bacteria with epithelial cells. The effect of azithromycin pretreatment (10 mg/kg/day) given by oral administration for 4 weeks was evaluated.ResultsIn naive cystic fibrosis mice, a spontaneous lung inflammation was observed, characterized by macrophage and neutrophil infiltration, and increased intra-luminal content of the pro-inflammatory cytokine macrophage inflammatory protein-2. After induced inflammation, cystic fibrosis mice combined exaggerated cellular infiltration and lower anti-inflammatory interleukin-10 production. In cystic fibrosis mice, azithromycin attenuated cellular infiltration in both baseline and induced inflammatory condition, and inhibited cytokine (tumor necrosis factor-α and macrophage inflammatory protein-2) release in lipopolysaccharide-induced inflammation.ConclusionOur findings further support the concept that inflammatory responses are upregulated in cystic fibrosis. Azithromycin reduces some lung inflammation outcome measures in cystic fibrosis mice. We postulate that some of the benefits of azithromycin treatment in cystic fibrosis patients are due to modulation of lung inflammation.

Intrahepatic cholangiocarcinoma: MRI and pathologic correlation in 14 patients

PURPOSE Our goal was to determine the MR features of intrahepatic cholangiocarcinoma and to correlate them with pathologic findings in a surgical series. METHOD MRI in 14 patients with intrahepatic cholangiocarcinoma who had undergone resection was reviewed. All patients had T1- and T2-weighted SE sequences. Contrast-material-enhanced MRI was performed in 12 cases. Comparison between findings at MRI and pathologic examination was made. RESULTS MRI depicted all the lesions but one satellite nodule of 2 cm diameter. All lesions were hypointense relative to the liver on T1-weighted images. On T2-weighted images, the tumors were predominantly isointense or slightly hyperintense relative to liver parenchyma in nine cases (64%) and were strongly hyperintense in five cases (36%). Central hypointense areas or bands were seen in eight cases. No capsule was detected. On contrast-enhanced MR studies, all lesions had progressive and concentric filling with contrast material. Associated findings such as vascular encasement, focal liver atrophy, or dilatation of intrahepatic bile ducts were observed in 10 cases (71%). Comparison with pathologic examination revealed that lesion signal intensity on T2-weighted MR images was due mostly to the amount of fibrosis, necrosis, and mucous secretion within the lesion. The nine isointense or slightly hyperintense lesions contained abundant fibrosis and had a low content of mucous secretion or necrosis, whereas the five hyperintense lesions contained low or moderate fibrosis and prominent mucous secretion and/or necrosis. CONCLUSION Our study suggests that the MR features of intrahepatic cholangiocarcinoma are well correlated with pathologic findings, but are nonspecific. Associated findings may strengthen the diagnosis of intrahepatic cholangiocarcinoma at MRI.

Epithelioid hemangioendothelioma of the liver: MR and CT findings.

The MR imaging features in five patients with hepatic epithelioid hemangioendothelioma (EHE) were correlated with CT and pathologic findings. Two hemangioendotheliomas appeared as multiple nodular lesions with a predominantly peripheral location in the liver. In three more extensive cases, the tumors formed confluent peripheral lesions with macroscopic invasion of portal or hepatic veins (n = 3), signs of portal hypertension (n = 3), and nodular hypertrophy of uninvolved liver (n = 2). These findings, suggestive of EHE, were well demonstrated by MR imaging and CT. The internal architecture of the tumors was clearly depicted on T2-weighted MR images. Viable tumor peripheries appeared moderately hyperintense relative to liver. The center of the tumors consisted of one or several concentric zones. Hyperintense central zones were composed of loose, edematous connective tissue. Hypointense zones contained mainly coagulation necrosis, calcifications, and scattered hemorrhages. Except for the presence of calcifications, the internal architecture of EHE was better defined by MR imaging than by CT.

Combined bronchoalveolar lavage and transbronchial lung biopsy: safety and yield in ventilated patients.

The aim of this study was to evaluate the safety and diagnostic yield of bedside bronchoalveolar lavage (BAL) combined with fibrescopic transbronchial lung biopsy (TBLB) in determining the aetiology of pulmonary infiltrates in mechanically ventilated patients. The records of 38 mechanically ventilated patients who underwent BAL/TBLB to investigate unexplained pulmonary infiltrates were retrospectively reviewed. Patients were divided into two groups: immunocompetent (group 1: n=22; group 1a: n=11, late acute respiratory distress syndrome (ARDS); group 1b: n=11, no ARDS) and immunocompromised (group 2, n=16). The procedure allowed a diagnosis in 28 patients (74%), inducing therapeutic modification in 24 (63%) and confirmation of clinical diagnosis in four (11%). In groups 1a, 1b and 2, diagnosis was obtained in 11 out of 11 (fibroproliferation), seven out of 11 and 10 out of 16 patients, and therapy changed in 11 out of 11 (administration of steroids), six out of 11 and seven out of 16 patients, respectively. Pneumothorax occurred in nine patients (four of group 1a), bleeding in four (<35 mL), and transient hypotension in two. No fatalities were procedure-related. Combined bronchoalveolar lavage/transbronchial lung biopsy is of diagnostic and therapeutic value in mechanically ventilated patients with unexplained pulmonary infiltrates, excluding those with late acute respiratory distress syndrome. Although complications are to be expected, the benefits of the procedure appear to exceed the risks in patients in whom a histological diagnosis is deemed necessary.

Correcting vocal fold immobility by autologous collagen injection for voice rehabilitation. A short-term study.

We report on a short-term clinical study of injectable autologous collagen (Vocalogen) used to correct dysphonias arising from vocal fold immobility. The collagen is extracted from skin taken from the lower abdominal quadrant area or from just above the bikini line. About 30 cm2 of skin are required to provide 2 mL of injectable collagen. The histologic examination of the preparation before injection disclosed the presence of elastin fibers and some clusters of epithelial cells, beside the collagen fibers. The collagen is naturally reticulated, and the molecule is preserved in its entirety. The technique is exactly the same as that reported for bovine collagen: injection into Reinkes space, under general anesthesia, monitored by direct microlaryngoscopy. The amount injected is also similar: 1.5 mL for correction of glottic insufficiency in which the immobile vocal fold is in the intermediate position. Eight patients were injected, and the average follow-up was 4.5 months. Voice assessments made before and after the treatment included stroboscopy, subjective and perceptual judgments, and aerodynamic and acoustic measurements. The functional results were similar to those obtained with bovine collagen. No complications arose. The probability of any hypersensitivity reaction, always a possibility to be feared with bovine collagen, is negligible with the autologous collagen. Long-term results are as yet unknown, but from the fact that the collagen molecular structure is intact and there is little risk of foreign body response, it would be expected that autologous preparations would be more stable than bovine collagen; this appears to be the case in cosmetic applications. Autologous collagen could be employed for the same indications as bovine collagen, provided that a delay of 45 days (the time required to prepare the injectable collagen) is acceptable. The amount of collagen required is also a limiting factor, since the patients own skin is the starting donor material.

CO2 laser in the diagnosis and treatment of early cancer of the vocal fold.

A total of 74 patients underwent cordectomy using CO2 laser for either diagnosis or treatment of an early cancer of the vocal fold. Type I cordectomy consisted in the resection of the entire epithelium, while leaving the vocal ligament intact. Type II cordectomy involved removal of the vocal fold from the vocal process to the anterior commissure and passing through the inferior thyroarytenoid muscle. Type IIIA required vocal fold resection along the internal side of the thyroid ala, while type IIIB included removal of the anterior commissure. Type I cordectomies were carried out with an Acuspot micromanipulator, which provided a 250-μm-diameter beam for a working distance of 400 mm, and in the shot-by-shot cutting mode with 3 W power superpulse. This cordectomy was carried out in 39 patients and a dysplasia or an early carcinoma were detected in 45.9% of cases. Type II and type III procedures were performed with the Microslad micromanipulator having a 700-μm-diameter beam in the continuous cutting mode, 7 W power superpulse. Fifteen cases were treated by type II cordectomy, of which 3 T1aN0M0 cases underwent postoperative radiotherapy due to insufficient resections and 2 cases with T1bN0M0 tumors later underwent reconstructive laryngectomy. A type III cordectomy was used for 14 cases of TlaNOMO carcinomas and 3 cases of severe dysplasia. The margins of resection were found to be positive histologically in 23.5% of these cases, making frozen section examinations mandatory at time of surgery. Results of all procedures showed that voice was best after a type I cordectomy where only the epithelium was resected. In the type II and type III cordectomies, the quality of voice depended on the development of a fibrous fold and the absence of anterior synechia in the healed larynx.

Prognostic value of cell proliferation markers, tumour suppressor proteins and cell adhesion molecules in primary squamous cell carcinoma of the larynx and hypopharynx.

Abstract. In an attempt to identify molecular prognostic markers, a series of laryngeal and hypopharyngeal carcinomas was examined for PCNA, Ki67, p27Kip1, p53, E-cadherin and CD44 by immunohistochemistry and for DNA content by flow cytometry. No correlation was found between E-cadherin, CD44, p53 or DNA ploidy and the clinicopathological data. The fraction of cancer cells immunolabelled for p27Kip1 correlated with tumour differentiation, but not with lymph node metastasis. In contrast, the PCNA, Ki67 and S-phase fractions of cancer cells were significantly higher in tumours with lymph node metastasis than in those without lymph node metastasis and were correlated with pathological T-stages and with tumour dedifferentiation. In univariate analysis, advanced pathological T-stage, lymph node metastasis and high fractions of cancer cells immunolabelled for PCNA or Ki67 inversely correlated with overall and disease-free survival. In multivariate analysis, lymph node metastasis was the only factor significantly associated with poor survival. The data suggest that immunohistochemical investigation of PCNA and Ki67 and flow cytometric analysis of S-phase fractions may be useful predictive markers of biological aggressiveness in laryngeal carcinomas.

Increased galectin-3 expression and intra-epithelial neutrophils in small airways in severe COPD.

Galectins-1 and -3 regulate epithelial proliferation/apoptosis and neutrophil activation, and are implicated in lung cancer and asthma. The role of galectins in chronic obstructive pulmonary disease (COPD), characterised by epithelial changes and neutrophil infiltration, remains unknown. In the present study, galectin-1 and -3 expression was assessed by immunohistology in the bronchial epithelium of lung specimens from eight severe COPD patients and compared with nine nonsmokers and six smokers without COPD. Findings were related to epithelial proliferation (Ki-67), tissue inflammation and lung function. Epithelial galectin-3 immunostaining was increased only in the small airways of COPD patients when compared with nonsmokers and smokers. In contrast, galectin-1 was only significantly increased in the small airways of the group of smokers. Ki-67+ epithelial cells and neutrophils were increased in the small airways of COPD patients when compared with smokers. Furthermore, intra-epithelial neutrophils correlated in the small airways with Ki-67+ epithelial cells and with the forced expiratory volume in one second/forced vital capacity ratio. However, no correlation was observed with galectin expression. The present study supports the hypothesis that distal airways represent an important site for detecting changes in chronic obstructive pulmonary disease. In patients with severe disease, an increased galectin-3 expression and neutrophil accumulation in the small airway epithelium was demonstrated, correlating with epithelial proliferation and airway obstruction.

Platelet-Derived Growth Factor–Producing CD4+ Foxp3+ Regulatory T Lymphocytes Promote Lung Fibrosis

RATIONALE There is evidence that CD4(+) effector T lymphocytes (T eff) participate in the development of lung fibrosis, but the role of their CD4(+) regulatory T-cell (T reg) counterparts remains to be determined. OBJECTIVES To elucidate the contribution of T reg cells in a mouse model of lung fibrosis induced by silica (SiO(2)) particles. METHODS Lung T reg and T eff cells purified from SiO(2)-treated Foxp3-GFP transgenic mice were cocultured with naive lung fibroblasts or transferred to the lungs of healthy mice. DEREG mice, which express the diphtheria toxin receptor under the control of the foxp3 gene, were used to deplete T reg cells during fibrogenesis. MEASUREMENTS AND MAIN RESULTS CD4(+) Foxp3(+) T reg cells were persistently recruited in the lungs in response to SiO(2). T reg accumulation paralleled the establishment of pulmonary immunosuppression and fibrosis. T reg cells highly expressed platelet-derived growth factor (PDGF)-B via a TGF-β autocrine signaling pathway, directly stimulated fibroblast proliferation in vitro, and increased lung collagen deposition upon transfer in the lung of naive mice. The direct profibrotic effects of T reg cells were abolished by the inhibitor of the PDGF-B/TGF-β signaling pathway, imatinib mesylate. Neutralization of T reg-immunosuppressive activity resulted in enhanced accumulation of T eff cells and IL-4-driven pulmonary fibrogenesis, further demonstrating that T reg cells control T eff cell functions during inflammatory fibrosis. CONCLUSIONS Our study indicates that T reg cells contribute to lung fibrosis by stimulating fibroblasts through the secretion of PDGF-B in noninflammatory conditions and regulate detrimental T eff cell activities during inflammation-related fibrosis.