Effect of Silica Inhalation on the Pulmonary Clearance of a Bacterial Pathogen in Fischer 344 Rats

Silica inhalation predisposes workers to bacterial infection and impairments in pulmonary defense function. In this study, we evaluated the effect of pre-exposure to silica on lung defense mechanisms by use of a rat pulmonary Listeria monocytogenes infection model. Male Fischer 344 rats were exposed by inhalation to filtered air or silica (15 mg/m³× 6 h/day × 5 days/wk). After 21 or 59 days of silica exposure, the rats were inoculated intratracheally with 5 × 10³ L. monocytogenes. At 0 (noninfected controls), 3, and 7 days after infection, the left lungs were removed, homogenized, and the number of viable L. monocytogenes was counted after an overnight culture at 37° C. Bronchoalveolar lavage (BAL) was performed on the right lungs. Alveolar macrophages (AM) were collected, and the AM production of chemiluminescence (CL), an index of reactive oxygen species generation, was measured. The number of lavagable neutrophils (PMNs) and acellular BAL lactate dehydrogenase (LDH) activity were determined as indices of inflammation and injury, respectively. Pre-exposure to silica for 59 days caused substantial increases in PMN number and LDH activity compared with the air controls, whereas silica inhalation for both 21 and 59 days significantly enhanced the pulmonary clearance of L. monocytogenes compared with air controls. Dramatic elevations were also observed in zymosan- and phorbol myristate acetate (PMA)–stimulated CL production by lung phagocytes recovered from rats pre-exposed to silica for 59 days. These results demonstrate that short-term exposure to inhaled silica particles activates lung phagocytes, as evidenced by increases in reactive oxygen species. This up-regulation in the production of antimicrobial oxidants is likely responsible for the enhancement in pulmonary clearance of L. monocytogenes observed with short-term silica inhalation. Accepted for publication: 2 October 2000     

Interchangeability of biosimilar and biological reference product: updated regulatory positions and pre- and post-marketing evidence

Introduction: Since 2006, biosimilars have been available in several countries worldwide, thus allowing for potential savings in pharmaceutical expenditure. However, there have been numerous debates about the interchangeability of biosimilars and reference products based on concerns of immunogenicity by switching between biological products, which may cause lack of effect and toxicity.

Areas covered: The authors provide the reader with an overview of the different positions of regulatory authorities on the interchangeability and automatic substitution of biosimilars and reference products. Presently, the FDA allows automatic substitution without prescriber intervention if the biosimilar is interchangeable with reference products, while the European Medicines Agency delegate to each single EU member state.

Expert opinion: Different approaches in defining interchangeability and automatic substitution call for harmonization to increase confidence of healthcare professionals and patients about the clinical impact of switching. Networks of electronic healthcare records and administrative databases, potentially linkable to clinical charts and registries may rapidly assess frequency and benefit-risk profile of different switching patterns in routine care at different levels, thus integrating and strengthening pre-marketing evidence.     

Non-coronary cardiac events,younger age,and IVIG unresponsiveness increase the risk for coronary aneurysms in Italian children with Kawasaki disease

Clinical Rheumatology - Kawasaki disease (KD) is the most frequent cause of acquired heart disease in children in high-income countries because of coronary artery involvement. Risk factors for...     

Chronic rejection after liver transplantation: Opening the Pandora’s box

Chronic rejection (CR) of liver allografts causes damage to intrahepatic vessels and bile ducts and may lead to graft failure after liver transplantation. Although its prevalence has declined steadily with the introduction of potent immunosuppressive therapy, CR still represents an important cause of graft injury, which might be irreversible, leading to graft loss requiring re-transplantation. To date, we still do not fully appreciate the mechanisms underlying this process. In addition to T cell-mediated CR, which was initially the only recognized type of CR, recently a new form of liver allograft CR, antibody-mediated CR, has been identified. This has indeed opened an era of thriving research and renewed interest in the field. Liver biopsy is needed for a definitive diagnosis of CR, but current research is aiming to identify new non-invasive tools for predicting patients at risk for CR after liver transplantation. Moreover, the minimization or withdrawal of immunosuppressive therapy might influence the establishment of subclinical CR-related injury, which should not be disregarded. Therapies for CR may only be effective in the “early” phases, and a tailored management of the immunosuppression regimen is essential for preventing irreversible liver damage. Herein, we provide an overview of the current knowledge and research on CR, focusing on early detection, identification of non-invasive biomarkers, immunosuppressive management, re-transplantation and future perspectives of CR.     

Non-alcoholic fatty liver syndrome: a hepatic consequence of common metabolic diseases

BACKGROUND AND AIMS: The association of liver steatosis with a number of common metabolic conditions has been suggested. The aim of the present study was to evaluate the clinical features of subjects with different severities of steatosis. METHODS: The present study was performed in 282 consecutive patients with 'bright liver' at ultrasonography and in 58 subjects without steatosis. They had no history of alcohol abuse and negative tests for the presence of hepatitis B and C virus. Patients underwent clinical examination, anthropometry, laboratory tests and routine liver ultrasonography. Steatosis was graded as absent, mild, moderate and severe. RESULTS: A progressive increase in the prevalence of obesity (P < 0.001), type 2 diabetes (P < 0.001), alanine aminotransferase (ALT) elevation (P < 0.001) and hypertriglyceridemia (P < 0.001), and a decrease of hypercholesterolemia (P < 0.05) was observed from the control group to the groups with mild, moderate and severe steatosis. More than half the subjects with liver steatosis had insulin resistance metabolic syndrome. Obesity, diabetes and hypertriglyceridemia were more common by 5.3-fold, 4.0-fold, and 6.7-fold, respectively, in subjects with severe steatosis, as compared to controls. Prevalence of obesity, diabetes and hyperlipidemia was significantly higher in subjects with fatty liver and ALT elevation. CONCLUSION: Fatty liver can be considered as the hepatic consequence of common metabolic diseases.     

18F-FDG PET/CT as predictive and prognostic factor in esophageal cancer treated with combined modality treatment

Annals of Nuclear Medicine - [18F] fluorodeoxyglucose positron emission tomography/computed tomography ([18F] FDG-PET/CT) is used for diagnosis, staging, response assessment and prognosis...     

Bone marrow-resident memory T cells survive pretransplant chemotherapy and contribute to early immune reconstitution of patients with acute myeloid leukemia given mafosfamide-purged autologous bone marrow transplantation

OBJECTIVE: Studies of memory T cells transferred with the graft are relevant to better understand the early immune reconstitution of patients given autologous bone marrow transplantation (A-BMT). A critical question is whether memory T cells resident in bone marrow (BM) of patients with hematological malignancies are resistant to either pretransplant chemotherapy or ex vivo pharmacological purging. PATIENTS AND METHODS: To address these issues, we evaluated the frequency of tetanus-toxoid (TT)-specific proliferating T-cell precursors (TT-PTCp) in BM and peripheral blood (PB) of eight patients with acute myeloid leukemia (AML) given A-BMT after in vitro purging of BM with mafosfamide. Patients were studied at the time of BM harvesting and five of them also after A-BMT. RESULTS: The range of TT-PTCp frequencies found after A-BMT were comparable with those observed in PB and in BM at the time of harvesting and did not differ significantly from those of eight age-matched healthy subjects who donated BM for a human leukocyte antigen-identical sibling. TT-PTCp frequencies in BM, studied before and after ex vivo purging, appeared not to be affected by incubation with mafosfamide. We also compared the T-cell receptor (TCR)-Vbeta-repertoire usage of TT-specific T-cell lines (TT-TCL) in BM of patients at the time of harvesting and in their PB 2 months after transplantation. The same TCR-clonotypes were detected in TT-TCL at time of harvesting and after A-BMT. CONCLUSION: These data indicate that BM-resident memory T cells of patients with AML are resistant to both pretransplant chemotherapy and ex vivo pharmacological purging and may contribute to immune reconstitution after A-BMT.