Daniel H. Matulionis

Fine Structure of the Vomeronasal Neuroepithelium of Bats: A Comparative Study

The vomeronasal neuroepithelium of the vampire bat, Desmodus rotundus, and the frugivorous bats, Carollia perspicillata and Artibeus jamaicensis, was examined at the light-microscopic and ultrastructural levels. The neuroepithelium of these species is basically similar in morphology to that of other mammals. However, hitherto unknown differences were noted in regard to the configuration of the apical poles of cells, in the occurrence of solitary cilia, dislocated sensory cells, brush cells, cell contacts and the occurrence and fine structure of basal cells. The morphology of the vomeronasal neuroepithelium of all three species is discussed from a comparative point of view in regard to chemoreception.

Pneumatic tourniquet application and nerve integrity: Motor function and electrophysiology

Limb motor function, leg girth, spontaneous potentials, and compound muscle action potentials were evaluated in a rat animal model at various times after tourniquet application and occlusion of blood flow to the sciatic nerve. The thighs of the animals were compressed by a pneumatic tourniquet at clinically relevant pressures (200, 300, and 400 mm Hg) for 1 to 3 h. Extrinsic blood supply was occluded by ligation of the common iliac and femoral arteries and intrinsic by removing a 12-mm segment of the epineurium from the sciatic nerve. Motor function deficits were noted for 1 to 5 weeks in limbs of animals subjected to tourniquet compression and from 2 to 4 weeks following vascular manipulation. Control leg girths did not change during the experiment whereas girths of tourniquet-compressed legs increased initially and then decreased and remained below control values. Girths of limbs subjected to vascular manipulation were unaltered during the 1st week but decreased in a similar fashion to those of tourniquet-compressed limbs at 3 and 6 weeks. Spontaneous potentials were present and compound muscle action potentials were reduced in animals after tourniquet application and vascular manipulation compared with control values. These electrical abnormalities were most pronounced 1 week after the treatments, progressed toward normalcy during the course of the experiment, but failed to attain control values at the termination of the study. Analysis of electrophysiologic data indicated that magnitude of pressure and duration of compression-produced nerve injury occurred independently in an additive fashion.

Chronic Cigarette Smoke Inhalation and Aging in Mice: 1. Morphologic and Functional Lung Abnormalities

The effects of long-term cigarette smoke inhalation on the morphologic and functional integrity of lungs of C57BL/6 young and old mice have been assessed. Smoke exposure occurred over a 9-month period beginning when the young animals were 2 months of age and the old mice 8-10 months. At the termination of the experiment, microscopic and morphometric evaluation of pulmonary tissue revealed peribronchiolar and perivascular accumulations of lymphocytes and macrophages in lungs of both young and old smoke-exposed mice. Such lesions were never observed in sham-treated or control animals of either age. These observations indicate that lesions in mice can be induced by long-term smoke inhalation. In addition, three other anomalous manifestations, prominent only in the smoke-exposed old animals, were noted: 1) reduction of alveolar space with a concomitant increase in lung cellularity and thickened alveolar septa; 2) intra-alveolar accumulation of surfactantlike material; and 3) decreased pulmonary function. Since these abnormalities were prominent only in smoke-exposed old animals, an interaction between smoke inhalation and aging is indicated. Pulmonary function data complement morphologic and morphometric observations and indicate that the manifestation of abnormality noted in the old smoke-exposed animals are restrictive in nature and conform most closely to pulmonary fibrosis.

Chronic Cigarette Smoke Inhalation and Aging in Mice: 2. Quantitation of the Pulmonary Macrophage Response

Effects of chronic cigarette smoke inhalation on population size, cell dimensions and ultrastructure of in situ pulmonary macrophages of young and old C57BL/6 mice have been assessed. Smoke exposure occurred over a 9-month period beginning when young animals were 2 months of age and old mice 8 to 10 months. Quantitative data revealed that chronic smoke exposure significantly elevates the pulmonary macrophage population size over control values. However, the number of phagocytes was more than three times greater in young smoke-exposed mice when compared to that of the old. Mean area and diameter of pulmonary macrophages in young and old smoke-exposed animals were significantly larger than those of controls. Morphometric data indicate that pulmonary macrophage enlargement in old smoke-exposed animals was due to increased numbers and size of secondary lysosomes and accumulation of inclusions resembling crystalline kaolinite within the cells. More than one percent of cell volume was occupied by this material. Evaluation of dimensional changes of organelles involved in synthesis and metabolism suggests that smoke inhalation had no measurable effect on or slightly depressed these activities. Data reported indicate that the lysosomal system is altered differentially in smoke-exposed young and old animals.

Murine lung response to kaolin conveyed by cigarette smoke

The effects of chronic (3 to 8.5 months) smoke inhalation from cigarettes laced with 0.1, 1.0 and 10.0 mg kaolin (hydrated aluminum silicate) per gram of tobacco on the morphological integrity of lungs and the pulmonary macrophage population were evaluated in young and old male C57BL/6 mice. Lacing procedures, monitored by determining aluminum content in acid-digested aliquots of tobacco via atomic absorption spectrometry (AAS), proved to be uniform. Amounts of aluminum in right lungs of young mice evaluated by AAS and of kaolin assessed by electron diffraction and polarizing light microscopy were larger in mice which inhaled smoke from cigarettes laced with more kaolin. A more pronounced increase in lung parenchymal tissue and decrease of alveolar space was observed in old mice subjected to smoke from cigarettes containing higher doses of kaolin than in similarly treated young animals. Concomitant with the above, the lung macrophage population did not increase as markedly in response to smoke inhalation in old mice nor did it increase in as clear a dose-response fashion to kaolin as it did in young animals. Further, the degree of ultrastructural alteration of the phagocytes in the old mice suggested impaired cell function. Plate-like material resembling kaolin crystals was most conspicuous in lung macrophages of mice which inhaled largest amounts of kaolin. Manifestations of abnormal aggregates of lymphocytes and macrophages correlated with kaolin dose inhaled in old mice but not in young animals. The reported observations indicate that 1) kaolin gains access to lungs via cigarette smoke inhalation, 2) macrophages are important in maintaining pulmonary homeostasis and 3) the inorganic compound kaolin appears to impede macrophage function, resulting in potentiation of lung abnormalities.

Morphologic and physiologic response of lungs to steroid and cigarette smoke: an animal model

The combined effects of cigarette smoke inhalation and hydrocortisone acetate (HCA) treatment induce prominent abnormalities in lungs of C57BL/6 male mice. These abnormalities include (1) a marked reduction of pulmonary macrophage population which is normally elevated by smoke inhalation, (2) an accumulation of surfactant and flocculent material in alveoli, (3) a decrease in alveolar space surrounded by normal septal tissue, and (4) an increase in hypertrophied alveolar parenchyma. Concomitant with altered lung morphology, lung volume and gas diffusing capacity were significantly compromised in animals subjected to smoke exposure and steroid treatment. It was found that smoke inhalation or HCA administration alone had no ill effects on the animals. The data presented indicate that manifestation of pathologic conditions resembling pulmonary fibrosis and pulmonary alveolar proteinosis is a result of cigarette smoke-drug interaction. The information reported provides a basis for an animal model which might be applicable to assessment of factors related to smoke inhalation and development of pulmonary disorders.

Pulmonary tissue and cigarette smoke: 1. Cellular response to hydrocortisone

Hydrocortisone acetate (HCA) administration significantly reduces the population of pulmonary macrophages and blood leukocytes in control, sham-treated, and smoke-exposed C57BL6J mice. This treatment impedes markedly the influx of macrophages from bone marrow into the lungs. The small number of new phagocytes noted in lungs following HCA treatment appears to arise by proliferation of in situ pulmonary macrophages. Mortality rate of sham-treated and smoke-exposed mice was approximately twice that of control animals following HCA treatment. While severe pulmonary disorders were noted in lungs of HCA-treated, smoke-exposed animals, considerably milder abnormalities were seen in lungs of sham-treated mice. The data reported indicate that physical stress generated by manipulation during sham and smoke treatment, exposure to cigarette smoke, and reduction of pulmonary macrophages and leukocyte populations by HCA administration are factors which adversely affect pulmonary integrity and survival time of the animals.

Lung deformation and macrophage displacement in smoke-exposed and normal mice (Mus musculus) following different fixation procedures

Lung deformation (shrinkage or inflation) and displacement of pulmonary parenchymal macrophages were evaluated after immersion fixation, intratracheal instillation of fixative and lung lavage followed by intratracheal fixative instillation in cigarette smoke-exposed, sham-treated and control pallid male mice. Lung volume displacement and lung section and alveolar area analysis revealed that degree of deformation was uniform in lungs from all treatment groups fixed by immersion but not by instillation of fixative and fixative instillation following lavage. In situ pulmonary parenchymal macrophage number per lung section area of fixative-instilled lungs and lavaged lungs followed by fixative instillation was significantly greater than in those following immersion fixation in all corresponding treatment groups. A paucity of macrophages was noted in airways of fixative-instilled and lavaged followed by instillation of fixative lungs. Pulmonary macrophages were uniformly distributed throughout lung parenchyma following immersion fixation, while in fixative-instilled and lavaged prior to instillation of fixative lungs these cells tended to be concentrated in alveoli near terminal bronchioles. Lavage procedures removed an unknown portion of lung macrophages and appeared to ineffectively sample the pulmonary parenchymal macrophage population. Intratracheal instillation of fixative with or without prior lavage apparently alters the distribution of pulmonary macrophages by displacing airway phagocytes into the alveoli. Data reported suggest that fractional estimates of in situ lung parenchymal macrophage population can be obtained by counting the number of these cells per area of tissue from lungs fixed by immersion.

Pulmonary tissue and cigarette smoke. 2. Parenchymal response.

Cigarette smoke and hydrocortisone acetate (HCA) induce marked abnormalities in lungs of C57BL/6J male mice. In many pulmonary regions of smoke-exposed, HCA-treated animals, alveoli were highly congested with surfactant and flocculent material. In addition, prominent alveolar collapse and septal hypertrophy were common. These conditions resembled pulmonary alveolar proteinosis described in humans. Administration of HCA to sham-treated animals also produced lung abnormalities, however, considerably milder in severity, while stress (resulting from sham treatment) or HCA injections of mice alone failed to induce any pulmonary tissue disorder. Data reported indicate that the genesis of abnormal conditions which resemble pulmonary alveolar proteinosis is potentiated by cumulative effects of different treatments (i.e., smoke, HCA, and stress), most significant being the interaction between cigarette smoke and the steroid.