ABSTRACT
INTRODUCTION: The role of allergy in eustachian tube dysfunction is controversial. In this study, allergy was simulated by exposure to histamine, and eustachian tube function testing was performed in an experimental rat model. METHODS: Ventilatory function was assessed by measuring passive opening and closing pressures of the eustachian tube after challenge with either transtympanic or intranasal histamine. The mucociliary clearance time of the tubotympanum was assessed by observing dye transport from the middle ear to the nasopharynx after challenge with either transtympanic histamine or control solution. RESULTS: There was a statistically significant increase in passive opening and closing pressures with transtympanic histamine versus intranasal histamine. In addition, mucociliary clearance times of the tubotympanum after transtympanic histamine showed a statistically significant increase when compared with those after transtympanic control solution. CONCLUSIONS: Transtympanic histamine exposure causes eustachian tube dysfunction in the rat by increasing passive opening and closing pressures of the eustachian tube and impairing mucociliary clearance time.
Subject(s)
Eustachian Tube/drug effects , Histamine/pharmacology , Administration, Intranasal , Administration, Topical , Animals , Eustachian Tube/physiopathology , Histamine/administration & dosage , Labyrinth Diseases/physiopathology , Mucociliary Clearance/drug effects , Rats , Rats, Sprague-Dawley , Time Factors , Tympanic Membrane/drug effectsABSTRACT
BACKGROUND: Carbon dioxide (CO(2)) pneumoperitoneum has been implicated as a possible factor in depressed intraperitoneal immunity. Using in vitro functional assays, CO(2) has been shown to decrease the function of peritoneal macrophages harvested from insufflated mice. However, an effective in vivo assessment is lacking. Listeria monocytogenes (LM), an intracellular pathogen, has served as a well-established in vivo model to study cell-mediated immune responses in mice. This study examines the immune competence of mice based on their ability to clear intraperitoneally administered LM following CO(2) vs helium (He) insufflation. METHODS: Eighty-five mice (C57Bl/6, males, 4-6 weeks old) were divided between the following four treatment groups: CO(2) insufflation, He insufflation, abdominal laparotomy (Lap), and control (anesthesia only). Immediately postoperatively, each group was inoculated percutaneously and intraperitoneally with a sublethal dose (.015 x 10(6) org) of virulent LM (EGD strain). Half of the animals were killed on postoperative day 3 and half on day 5. Spleens and livers (sites of bacterial predilection) were harvested, homogenized, and plated on TSB agar. The amount of bacteria (1 x 10(6) LM/spleen and liver) from each group was then compared. Statistical significance was set at p
Subject(s)
Carbon Dioxide/adverse effects , Immunity, Cellular , Liver/microbiology , Pneumoperitoneum, Artificial/adverse effects , Spleen/microbiology , Animals , Colony Count, Microbial , Helium , Laparoscopy , Listeriosis/immunology , Male , Mice , Mice, Inbred C57BLABSTRACT
Malignant mesothelioma is a well-recognized long-term sequela of chronic asbestos exposure. Asbestos use in the United States began in the 1950s and was widespread until the mid-1970s. Although currently only 2.2 cases per million population per year are diagnosed, disease incidence is increasing because of the long latency of this neoplasm. A latency of 15-50 years means that a higher incidence of this neoplasm can be anticipated in the future. The authors report a patient with peritoneal mesothelioma and no known prior exposure to asbestos. The diagnosis was confirmed by exploratory laparoscopy, which entailed biopsies of the diaphragm and of the peritoneal and abdominal walls, and by cytologic evaluation of 700 ml ascitis fluid. At present, exploratory laparoscopy offers the quickest, safest, and least invasive way to confirm the clinical diagnosis of peritoneal malignant mesothelioma.
