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Biomedical subjects

C Saito

Publications and source records attributed to C Saito.

At least 55 records · Page 3Linked to original sources

[The effect of leukotriene B4 inhalation on airway responsiveness in dogs].

We studied the effect of leukotriene B4 (LTB4) inhalation on airway responsiveness in 12 dogs. LTB4 (10 micrograms/ml) was delivered as an aerosol, generated from a Devilbiss 646 nebulizer for ten minutes. Airway responsiveness to inhaled methacholine was determined by modified Astograph (7 Hz oscillation method) 1 hr (n = 6) and 6 hr (n = 6) after LTB4 inhalation. After measurement of airway responsiveness, total cell counts, differential cell counts, thromboxane B2 (TxB2) and 6-keto-prostaglandin (PG)F1 alpha levels in bronchoalveolar lavage fluid (BALF) were measured. The total cell counts in BALF increased after LTB4 inhalation (p less than 0.05), and the neutrophil counts in BALF increased significantly 1 hr (p less than 0.05) and 6 hr after (p less than 0.01) LTB4 inhalation. Airway responsiveness to inhaled methacholine decreased significantly 1 hr (p less than 0.05) and 6 hr (p less than 0.01) after LTB4 inhalation. There were no significant changes in the levels of TxB2 or 6-keto-PGF1 alpha in BALF 1 hr and 6 hr after LTB4 inhalation. These results suggest that inhaled LTB4 causes neutrophil recruitment into the airway but does not increase airway responsiveness to inhaled methacholine, and the possibility that LTB4 reduces airway responsiveness to inhaled methacholine exists in dogs.

Administration, Inhalation↗

[The role of neutrophils in airway hyperresponsiveness in dogs after ozone exposure].

To determine whether neutrophils are involved in airway hyperresponsiveness after ozone exposure, we studied the effect of neutrophil depletion by cyclophosphamide treatment on ozone-induced airway hyperresponsiveness in seven dogs. Airway responsiveness to inhaled methacholine was determined by modified Astograph (7 Hz oscillation method), and the numbers of neutrophils in the peripheral blood, total cell counts and differential cell counts in BALF were measured before and after ozone exposure, and after ozone exposure of dogs undergoing cyclophosphamide treatment. Ozone exposure was carried out for 2 hrs at an ozone level of 3.07 +/- 0.01 ppm (mean +/- SE), and cyclophosphamide (10 mg/kg) was given intravenously daily for five days starting six days before ozone exposure. There was a significant increase in airway responsiveness to inhaled methacholine after ozone exposure in the seven dogs (p less than 0.001), and the numbers of neutrophils in the peripheral blood and the neutrophil counts in BALF increased significantly after ozone exposure (p less than 0.01). After ozone exposure of dogs undergoing cyclophosphamide treatment, the numbers of neutrophils in the peripheral blood decreased significantly (p less than 0.001) and the neutrophil counts in BALF did not increase, but the airway responsiveness to inhaled methacholine increased significantly (p less than 0.01). There was no significant correlation between the degree of the increase in airway responsiveness and the degree of the increase in neutrophil counts in BALF after ozone exposure. These results suggest that neutrophil infiltration into the airway is not necessary for an increase in airway responsiveness after ozone exposure in dogs.

Airway Resistance↗

[The effect of a selective 5-lipoxygenase inhibitor, AA-861 on airway hyperresponsiveness induced by ozone exposure in dogs].

To determine whether 5-lipoxygenase products are involved in hyperresponsiveness induced by ozone exposure, we studied the effect of a selective 5-lipoxygenase inhibitor, AA-861 on ozone-induced airway hyperresponsiveness in six dogs. Airway responsiveness to methacholine was measured by modified Astograph (7 Hz oscillation method) before and after ozone exposure, and TxB2 in plasma and in BALF, 6-keto-PGF1 alpha in BALF, numbers of neutrophils in the peripheral blood and differential cell counts in BALF were measured before and after ozone exposure. Ozone exposure was carried out for 2 hr at an ozone level of 3.04 +/- 0.01 ppm (mean +/- SE). There was a significant increase in airway responsiveness to methacholine after ozone exposure in the six dogs (p less than 0.01), and the numbers of neutrophils in the peripheral blood and the neutrophil counts in BALF increased significantly after ozone exposure (P less than 0.01). A selective 5-lipoxygenase inhibitor, AA-861 significantly inhibited the increase of airway responsiveness to methacholine induced by ozone exposure (p less than 0.05), and furthermore, the increase in the numbers of neutrophils in the peripheral blood and the neutrophil counts in BALF after ozone exposure were significantly inhibited by pretreatment with AA-861 (p less than 0.05). There was no significant change in the levels of TxB2 in plasma or in BALF, and also no apparent change in the levels of histamine was observed in BALF after ozone exposure. The levels of 6-keto-PGF1 alpha in BALF decreased after ozone exposure, but the decrease was not significant. These results suggest that 5-lipoxygenase products play an important role in the development of airway hyperresponsiveness and in the infiltration of neutrophils into the airway after ozone exposure in dogs.

Animals↗

Nodular fascitis of the mandible in a child.

Nodular fascitis is an unusual, tumor-like, proliferative, fibroblastic lesion with infiltrative properties. We describe a case of nodular fascitis appearing in the mandible of a 2-year-old boy. A brief review of the literature on this lesion arising from intra or perioral regions, and the importance of differential diagnosis for this lesions are discussed.

Child, Preschool↗

A case of primary B-cell lymphoma of the breast. Light and electron microscopy, and immunologic cell markers.

A case of primary non-Hodgkin's lymphoma of the breast was studied with light and electron microscopy and for immunologic cell markers. With light microscopy, the tumor was seen to be a poorly differentiated lymphocytic lymphoma, diffuse, according to Rappaport's classification. With electron microscopy, the tumor was seen to consist of a cytologically uniform cell population. The cells were characterized by irregularly shaped nuclei with infrequent cytoplasmic projections and "microvilli-like" structures, mimicking small cleaved follicular center cells. The immunologic cell marker study showed that the cells were positive for surface IgA and HLA-DR antigen; negative for SRBC receptors, Leu 1, Leu 2a, and Leu 3a antigens. The collective evidence indicated the tumor was of B-cell origin.

Adult↗