Oxidized phosphatidylcholine in alveolar macrophages in idiopathic interstitial pneumonias.

It has been suggested that oxidative stress plays a pathogenic role in idiopathic interstitial pneumonias. Macrophage- or neutrophil-derived oxidants seem to be important sources of oxidative stress in this group of inflammatory disorders. Recent experimental studies have revealed that oxidative injury during inflammation or apoptosis can change phosphatidylcholine of cell membrane into its oxidized form, which serves as a ligand for macrophage scavenger receptor CD36. Recently, we developed a monoclonal antibody against oxidized phosphatidylcholine. Using this novel antibody, we performed an immunohistochemical investigation to clarify the localization of oxidized phosphatidylcholine in lung tissues of idiopathic interstitial pneumonias and a relationship between oxidized phosphatidylcholine localization and CD36 expression. Lung specimens obtained from patients with desquamative (n = 8) or usual interstitial pneumonia (n = 15) were studied. Thirteen normal lung tissues were also examined as controls. Antibodies against oxidized phosphatidylcholine, CD36, epithelial cells, macrophages, and neutrophils were used as primary antibodies. The positive cell number was counted by computer-aided morphometry. While there were no oxidized phosphatidylcholine-positive cells in normal lungs, lungs of desquamative or usual interstitial pneumonia contained large numbers of oxidized phosphatidylcholine-positive cells in the alveolar spaces. Double-staining analysis revealed that most oxidized phosphatidylcholine-positive cells were macrophages. The oxidized phosphatidylcholine-positive cells were increased in association with the increase in the densities of macrophages (Rs = 0.87, p < 0.0001) and neutrophils (Rs = 0.89, p < 0.0001). Accumulated macrophages also showed distinct CD36 expression. These findings suggest that oxidative stress and the related product, oxidized phosphatidylcholine, play an important role in the pathophysiology of idiopathic interstitial pneumonias.

Mast cell chymase expression in Helicobacter pylori-associated gastritis.

AIMS: To study the role of mast cell chymase in the inflammatory processes of human chronic gastritis. Experimental studies have shown that mast cell chymase stimulates inflammatory cell accumulation, and contributes to angiotensin II formation. METHODS AND RESULTS: Tissue sections from human stomachs with Helicobacter pylori-associated gastritis (surgery/autopsy n = 20; biopsy n = 16) and normal stomachs (n = 10) were studied using immunohistochemical single and double labelling techniques. Monoclonal antibodies used were directed against mast cell chymase, tryptase, neutrophils (CD66b, elastase, and myeloperoxidase), macrophages, T-lymphocytes, and interleukin (IL)-4. The expression of angiotensin-converting enzyme and angiotensin II type 1 receptor was investigated using immunohistochemical analysis and the reverse transcription-polymerase chain reaction. The number of chymase-positive mast cells was significantly higher (P < 0.0001) in H. pylori-associated gastritis than in normal stomachs. Increased expression of chymase in inflamed mucosa was closely related to an increase in the accumulation of neutrophils, macrophages, T-lymphocytes, and IL-4-positive cells. The expression of angiotensin-converting enzyme and angiotensin II type 1 receptor was not altered in gastritis specimens. CONCLUSIONS: These observations suggest that mast cell chymase may be an important mediator in the inflammatory processes of human H. pylori-associated gastritis.

Acceleration of stiffness in underperfused diabetic rat hearts by glyburide, a KATP channel blocker, and its prevention by levcromakalim and insulin.

OBJECT: To clarify the role of the KATP channels in myocardial dysfunction during underperfusion with norepinephrine (NE) in the diabetic heart, particularly the heart treated with sulphonylurea derivatives. METHODS: Isolated 6-week streptozotocin-diabetic rat hearts with a balloon in the left ventricle (LV) were paced and perfused with normoxic Krebs-Henseleit solution. Agents were infused for 15-25 min before as well as during 60-min underperfusion (2 ml/min/g heart weight) with 10(-6) M NE. Regional myocardial flow distribution was measured using dye microspheres. The effects of ex vivo glyburide (10(-6) M, a sulphonylurea anti-diabetic drug and a specific KATP channel inhibitor) on contractile dysfunction and abnormal regional myocardial energy metabolism were examined during underperfusion with NE in the absence of presence of levcromakalim (10(-4) M, a selective K+ channel opener) and insulin (2 mU/min/g heart weight). RESULTS: The flow rate was greater in the LV subendocardium than the subepicardium during normal perfusion, and smaller at 60-min underperfusion with NE. The LV diastolic tension and pressure during underperfusion with NE increased more rapidly in the presence of glyburide. At 60-min underperfusion with NE, the diastolic pressure elevation was still higher in the glyburide-treated heart, and decreases in tissue ATP, creatine phosphate (CP), energy charge, phosphorylation potential and CP/inorganic phosphate (P(i)) ratio, and increases in AMP, P(i) and lactate were more marked in the glyburide-treated heart, particularly in the LV subendocardium. Thus, ex vivo glyburide enhanced the increase in LV stiffness and abnormal myocardial energy metabolism during underperfusion with NE in diabetic hearts. These changes were reduced by levcromakalim to the level during underperfusion with NE without glyburide. Insulin did not prevent the glyburide-induced earlier exacerbation of the increase in LV stiffness during underperfusion with NE, but reduced the detrimental effects 20 min after the onset of underperfusion. CONCLUSIONS: KATP channels in the diabetic myocardium probably open during underperfusion with NE, and it helps delay the initiation of the increase in cardiac stiffness. Glyburide may have harmful effects in the ischemic diabetic heart; the myocardial KATP channel blockade during underperfusion with NE enhanced the increase in LV stiffness and abnormal myocardial energy metabolism. The glyburide-induced detrimental effects in the ischemic diabetic heart are prevented by levcromakalim and partly by insulin.

Isolation and sequencing of two alpha-globin genes alpha(A) and alpha(D) in pigeon and evidence for embryo-specific expression of the alpha(D)-globin gene.

By screening a pigeon genomic DNA library, we isolated a recombinant phage clone containing the alpha(A)-globin gene. The DNA sequence of the approximately 6kbp-long insert fragment of the phage clone was determined. The sequence suggested the existence of pigeon alpha(D)-globin gene located 3.1 kbp upstream from the alpha(A)-globin gene. The expression of the alpha(D)-globin in late embryo was also shown by the N-terminal amino-acid sequence of the intact globin chain. These results show that two adult alpha-globin genes, alpha(A) and alpha(D), exist in the pigeon genome, and the alpha(D)-globin is expressed at the late embryo stage. The stage-specific expression suggests the existence of regulatory elements and factors interacting to inhibit transcription at the adult stage.

3D analysis of nystagmus in peripheral vertigo.

Three-dimensional analysis of nystagmus was carried out in patients with peripheral vestibular diseases using a computerized image recognition technique developed by us. In the present study, we analyzed data from patients with Meniere's disease and vestibular neuritis with the central premise of localizing the pathology in the peripheral vestibular organs. In Meniere's disease, the recordings of all subjects showed two components of eye movements, namely the horizontal and torsional components. On the other hand, most of the patients with vestibular neuritis exhibited all three components of spontaneous nystagmus. The horizontal and vertical components of nystagmus in patients with vestibular neuritis were directed towards the contralateral side of the lesion and upwards. Based on these results and with reference to animal experiments that have related the eye movements with each labyrinthine end organ, it can be speculated that in Meniere's disease the pathological changes may involve all semicircular canals, whereas the main site of lesion in vestibular neuritis could be localized to the superior vestibular nerve.

Amino acid sequences of hemoglobin beta chains of five species of pinnipeds: Neophoca cinerea, Otaria byronia, Eumetopias jubatus, Pusa hispida, and Pagophilus groenlandica.

Pinnipeds (Otariidae, Odobenidae, and Phocidae) in the order Carnivora have one or two types (Hb I and Hb II) of hemoglobin components. These hemoglobins consist of identical beta chains and different alpha chains. We determined the complete amino acid sequences of the hemoglobin beta chain of three species of Otariidae (Australian sea lion, South American sea lion, and northern sea lion) and two species of Phocidae (ringed seal and harp seal) from intact beta chain and chemical cleavage fragments. The sequences are similar to beta chains of the already known sequences of pinnipeds. These sequences were compared with those of other carnivores (Mustelidae, Ursidae, Canidae, and Felidae) and adult human hemoglobin beta chain. Using Artiodactyla (pig) as an outgroup, we find that the tree constructed by means of phylogenetic analysis shows that Odobenidae is closest to Otariidae, and that Otariidae and Odobenidae are closer to Mustelidae than to Phocidae.

Amino acid sequence of alpha- and beta-polypeptide chains of turkey (Meleagris gallopavo) hemoglobin.

Two hemoglobin components are recognized in erythrocytes of the adult turkey (Meleagris gallopavo). We determined the amino acid sequences of turkey alpha A-, alpha D- and beta-globin from intact globin chains and chemical cleavage fragments. The sequences are highly similar to the hemoglobin of the Phasianidae, chicken, Japanese quail and pheasant. Turkey and pheasant beta-globin are identical. The amino acid sequence of turkey alpha A-globin differs by only one residue from chicken alpha A-globin. Phylogeny trees from alpha A-, alpha D- and beta-globin were constructed by the neighbor-joining method. Although the trees generated from alpha A- and beta-globin were similar, that from turkey alpha D-globin differed.