Increase In Inflammatory Cells Research Articles

Kinetics of cell infiltration and cytokine messenger RNA expression after intradermal challenge with allergen and tuberculin in the same atopic individuals

Background: Previous studies, in which one time point was used, have shown that cells infiltrating skin biopsy specimens taken during allergen-induced late-phase responses (LPR) had a TH2-like (interleukin-4 [IL]-4 and IL-5 mRNA+) cytokine profile, whereas in delayed-type hypersensitivity (DTH) there was a predominant TH1-type pattern.Objective: The study was designed to examine the kinetics of accumulation of inflammatory cells and cells expressing mRNA for TH2- or TH1-type cytokines in LPR and DTH elicited simultaneously in the same subjects.Methods: Immunocytochemistry (alkaline phosphatase anti-alkaline phosphatase technique) and in situ hybridization were used to analyze skin biopsy specimens taken during allergen-induced LPR.Results: In LPR elevated numbers of CD3+ and CD4+ cells, eosinophils, neutrophils, and IL-4 and IL-5 mRNA+ cells were detected as early as 1 hour after allergen challenge, with a peak at 6 hours, which was maintained for up to 96 hours. A small but significant delayed increase in macrophages, CD8+ and CD25+ cells, and IL-2 and Interferon-γ mRNA+ cells was also observed, but only at the 48-hour and 96-hour time points. In contrast, in DTH the numbers of CD3+, CD4+, and mRNA+ cells for IL-2 and interferon-γ were not elevated until 24 hours after challenge and peaked at 48 hours after injection. At 48 hours there was an additional small but significant increase in IL-4 and IL-5 mRNA+ cells. For both LPR and DTH the kinetics of the increases in inflammatory cells and cytokine mRNA-expressing cells paralleled the clinical response.Conclusions: In LPR accumulation of T cells and granulocytes, together with cells expressing mRNA encoding for TH2-type cytokines, is relatively rapid (i.e., within 1 to 6 hours), whereas in DTH the T cell/macrophage infiltration and appearance of cells expressing TH1-type cytokines are not apparent until 24 to 48 hours. In LPR there is a TH1-type (or possibly TH0) component at 48 to 96 hours, and in DTH there is an additionalTH2/TH0 response.

Acute responses of non-human primates to airway delivery of an adenovirus vector containing the human cystic fibrosis transmembrane conductance regulator cDNA.

Recombinant human adenovirus (Ad) vectors are leading candidates for human gene therapy for cystic fibrosis (CF) based on demonstration of efficient transfer of exogenous genes to rodent respiratory epithelium in vivo and human respiratory cells in vitro. The safety of Ad-mediated gene transfer to the respiratory epithelium and acute (up to 21 days) clinical responses to airway delivery of a replication-deficient recombinant, E1-, E3- Ad type 5-based vector containing the human cystic fibrosis transmembrane conductance regulator cDNA (AdCFTR) were evaluated in rhesus monkeys. Airway delivery of an Ad vector with the lacZ marker gene demonstrated beta-galactosidase expression in epithelial cells. Animals administered intratracheal AdCFTR demonstrated human CFTR cDNA expression in airway epithelial cells. Animals administered AdCFTR intranasal, and 24 hr later, intrabronchial [2 x 10(7) to 5 x 10(10) plaque-forming units (pfu), n = 12], in a fashion similar to a proposed human protocol, or only intrabronchial (10(11) pfu, n = 3), had no significant changes in clinical parameters compared to vehicle controls (n = 6). Microscopic analysis of the lung by necropsy or bronchoalveolar lavage demonstrated a dose-dependent increase in inflammatory cells, primarily lymphocytes, in the area where AdCFTR was delivered, which persisted for at least 2 months in some animals. Serum anti-Ad type 5 neutralizing antibody titers did not rise and shed Ad was not detected. The presence of AdCFTR DNA, analyzed by the polymerase chain reaction (PCR), was not detected in organs outside the lung. These data demonstrate that AdCFTR is well tolerated in non-human primates, although there is dose-dependent inflammation in the lung not clinically apparent.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunological response to intrathecal and systemic treatment with ganglioside antibody R-24 in patients with malignant melanoma

Murine monoclonal antibody (MAb) R-24 reacts with the ganglioside GD3 that is highly expressed on malignant melanoma. 2 patients with melanosis of the meninges received MAb R-24 intrathecally. Regressive changes in tumour cells were observed in both patients after intrathecal application of MAb R-24 (1–10 mg, 8–10 h, over 5–6 weeks). The first patient suffered from brain metastases and died a few weeks later, whereas the second achieved a complete remission with no evidence of disease 6 years after intrathecal R-24 treatment. No R-24-related neurotoxicity has occurred to date. The administration of MAb R-24 caused an increase of inflammatory cells in the cerebrospinal fluid (CSF) of both patients. Cytotoxic lymphocytes, cultured from the CSF, showed high cytolytic activity against allogeneic melanoma cells in vitro. In addition, 15 patients with advanced melanoma, in which the brain was not affected, were treated with R-24 intravenously using high dose R-24 (5 or 10 mg/m 2) or low dose R-24 (1 mg/m 2). No remissions were registered in the high dose group, with only 1 6 patients experiencing a mixed response. In contrast, 2 9 patients treated with low dose R-24 achieved a partial remission, one achieving a minor response and the other a mixed response. Toxicity was related to the dose of R-24 administered. Urticaria, burning and pruritus were the prominent side-effects, mostly occurring at the high dose level. Immunological monitoring during and after intravenous treatment showed no significant changes in peripheral blood lymphocytes, natural killer cell activity or antibody-dependent cellular cytotoxicity, although transient changes were observed. There was no correlation between immunological parameters and clinical response.

Radiation Pneumonitis: Bronchoalveolar Lavage Assessment and Modulation by a Recombinant Cytokine

A common side effect of radiotherapy is the development of fibrosis in the irradiated tissue. To study the mechanisms of this fibrogenic response, we developed a model system of whole-lung radiation in the rat and studied the evolution of injury by assessment of the cells and protein recovered by lavage. Once the pattern of injury was known, we attempted to modulate this reaction by administering the cytokine interferon-gamma (IFN-gamma). Rats received 15 Gy radiation to the whole thorax and were studied by lung lavage at intervals of 1 to 35 days after radiation. The effect of radiation was an initial (24 h) leak of protein, unaccompanied by cellular alterations, that resolved by 48 h. This was followed 2 wk later by a phase of inflammatory cell recruitment and more significant protein leak. A third phase of increase in inflammatory cells and further increase in protein flux was noted at Day 35. A significant cellular infiltrate was seen in lung sections obtained from animals treated in parallel experiments. IFN-gamma was given by osmotic pump from Day 0 to Day 35. This treatment significantly attenuated the PMN recruitment and protein leak (p < 0.002 and 0.01, respectively) at Days 25 and 35. Histologic sections demonstrated reduced alveolar cellularity and exudate at Day 25 (p < 0.05); however, significant numbers of inflammatory cells and exudate were present in irradiated and IFN-gamma-treated animals at Day 35. These data indicate that inflammatory cell recruitment may play a role in the lung injury following radiation. Furthermore, these preliminary data indicate that a cytokine blocks this reaction.

The effects of a combined contraceptive vaginal ring releasing ethinyloestradiol and 3-ketodesogestrel on vaginal flora

Fifty nine women with documented normal ovulatory cycles and with no symptoms of vaginal infection were divided into four groups. Each group used a combined contraceptive vaginal ring (CCVR) with a mean daily release rate of 0.015 mg of ethinyloestradiol (EE) and 0.120 mg of 3 - ketodesogestrel (3-KDG) per day, for one cycle of either 21, 28, 42, or 56 days. Cultures from the posterior vaginal fornix and from the endocervical canal were obtained immediately before insertion of the ring and on removal of the ring. Changes in the numbers of vaginal cells, aerobic and anaerobic bacteria, Chlamydia trachomatis, Gardnerella vaginalis, yeasts and Trichomonas vaginalis were documented at the end of each treatment. Intra- and inter- group changes in the vaginal flora were assessed at the end of each treatment. The comparison between the number and type of flora showed no significant change between the pre-treatment population and the post-treatment population. The results of this study suggest that the use of this CCVR for 21, 28, 42 and 56 days is not associated with an increase in inflammatory cells or pathogenic bacteria.

Effect of antigen dose on the recruitment of inflammatory cells to the lung by segmental antigen challenge

Bronchoscopic antigen challenge of atopic volunteers results in an immediate release of inflammatory mediators and, after a number of hours, the recruitment of inflammatory cells to the lung. The purpose of this work was to investigate the effect of antigen dose on the subsequent recruitment of inflammatory cells to the lung. Twenty-two volunteers without asthma, eight nonatopic control subjects, and 14 ragweed-allergic subjects underwent 25 local antigen-challenge procedures that consisted of a baseline lavage of a control segment, antigen challenge of another segment in the contralateral lung, and lavage of the challenged segment 24 hours later. A 25,000-fold range of antigen doses was used from 0.004 to 100 PNU/ml (0.02 to 500 ng/ml of ragweed antigen E [ Amb aI]). Challenge of nonatopic control subjects resulted in the recruitment of only a small number of inflammatory cells, less than a twofold increase in comparison with the cells of control lavage; this increase was primarily due to an increase in neutrophils. Challenge of atopic subjects, in contrast, resulted in approximately a threefold to ninefold increase in inflammatory cells with more cells recruited at larger doses of antigen. Only subjects challenged with a “high” dose of antigen (≥1 PNU/ml) recruited significant quantities of eosinophils to the lung. In these subjects, a twofold increase in macrophages, a fourfold increase in lymphocytes, a 90-fold increase in neutrophils, and an 800-fold increase in eosinophils were observed; the number of neutrophils and eosinophils recruited averaged between 30 and 60 million. There was a direct relationship between the log of the dose of antigen used for challenge and the log of the number of eosinophils recruited ( r = 0.75; p < 0.001). We conclude that the dose of antigen used for local antigen challenge is an important factor that affects both the number and type of inflammatory cells recruited to the lung.

Long-term partial ureteral obstruction and its effects on kidney function.

Previously it has been shown that partial ureteral obstruction present in young rats for 12 weeks results in small morphological changes in the kidney as well as slightly decreased kidney function. In the present study the aim was to examine whether rats obstructed for one year had more advanced changes in morphology and kidney function. The first group of animals examined after three weeks of obstruction showed only modest changes in kidney function with a reduced potassium concentration in the urine but no reduction in the glomerular filtration rate. After one year there was a reduction in urine flow as well as in the excretion of both potassium and sodium. Urine osmolality was also reduced. Glomerular filtration rate measured in this group of animals was reduced in the obstructed kidney by about 60% compared to the contralateral one. There were only small changes in the morphology with no loss in parenchymal weight or compensatory hypertrophy, but there was a significant deformation of the papilla and an increase in inflammatory cells in the parenchyma. In conclusion hydronephrosis during a shorter period is not harmful to kidney function but if sustained for an extended time period kidney function will deteriorate.

Characterization of allergen-induced bronchial hyperresponsiveness and airway inflammation in actively sensitized Brown-Norway rats

Bronchial responsiveness to inhaled acetylcholine (ACh) and inflammatory cell recruitment in bronchoalveolar lavage fluid (BALF) were studied in inbred Brown-Norway rats actively sensitized to, and later exposed to, ovalbumin (OA). We examined animals 21 days after initial sensitization at 18 to 24 hours, or 5 days after a single challenge, or after the last of seven repeated exposures administered every 3 days. BALF was examined as an index of inflammatory changes within the lung. Animals repeatedly exposed to OA aerosols had an increased baseline lung resistance and a significant increase in bronchial responsiveness to inhaled ACh compared to control animals at both 18 to 24 hours and 5 days after the last OA exposure. Sensitized animals receiving a single OA aerosol also demonstrated bronchial hyperresponsiveness (BHR) to inhaled ACh ( p < 0.01) at 18 to 24 hours of a similar order as the multiple-exposed group. There was a significant increase in eosinophils, lymphocytes, and neutrophils in BALF at 18 to 24 hours but not at 5 days after single or multiple exposure to OA aerosol in the sensitized groups. Control animals demonstrated no changes in bronchial responsiveness, although a small but significant increase in inflammatory cells was observed compared to saline-only treated animals. There was a significant correlation between bronchial responsiveness and eosinophil counts in the BALF in the single allergen-exposed group ( R 5 = 0.68; p < 0.05). We conclude that (1) BHR after allergen exposure in sensitized rats is associated with the presence of pulmonary inflammation but persists despite the regression of inflammatory cells in BALF after multiple OA exposures, and (2) this rat model has many characteristics of human allergen-induced BHR.

Pulmonary hypertension induced by amosite asbestos: A physiological and morphologic study in the guinea pig

Although there is increasing evidence that mineral dust exposure will produce obstructive lung disease, there is little information on the effects of mineral dust on the pulmonary vascular system. To examine whether exposure to amosite asbestos would affect the pulmonary vasculature and produce pulmonary hypertension, we instilled 5 mg amosite asbestor intratracheally into guinea pigs. After periods of 3 and 6 months, we examined their pulmonary and pulmonary vascular function, and compared these data to those obtained from groups of control animals. We found that, at both time periods, there was pulmonary arterial hypertension, with alteration of the vascular pressure-flow relationships. This was accompanied by abnormalities in the structure of the small pulmonary arterioles. The animals also showed airflow obstruction, with air trapping and an upward shift of the pressure-volume curve. There was evidence of emphysema, and the animals were moderately hypoxic. We found no consistent increase in inflammatory cells either in lavage or peripheral blood, and the histamine dose-response curves were similar in control and asbestos-exposed animals at 6 months. We conclude that intratracheal instillation of asbestos in the guinea pig produces pulmonary hypertension associated with modest hypoxia, emphysema, and airflow obstruction. Whether pulmonary hypertension reflects emphysema-induced hypoxia and loss of vascular bed, or is related to the brief but intense inflammatory infiltrate induced by asbestos, is unclear.

Effect of capsaicin on PAF‐induced bronchial hyperresponsiveness and pulmonary cell accumulation in the rabbit

1 Platelet activating factor (PAF), but not the carrier molecule bovine serum albumin (BSA) induced bronchoconstriction in the anaesthetized rabbit. This bronchoconstriction was not altered by prior treatment with capsaicin. 2 Rabbits demonstrated increased airways responsiveness to histamine 24h after exposure to PAF but not to BSA. PAF failed to increase airways responsiveness to histamine in animals pretreated with capsaicin (80 mg kg-1). 3 A significant increase in inflammatory cells was obtained in bronchoalveolar lavage (BAL) 24h after PAF exposure in vehicle-treated rabitts. This was associated with an increase in the numbers of neutrophils and eosinophils. Capsaicin treatment inhibited the PAF-induced influx of inflammatory cells found in BAL, although this was not associated with an inhibition of PAF-induced pulmonary eosinophilia. 4 Capsaicin-induced motor effects were modest in epithelium-intact rabbit bronchial preparations, but were significantly enhanced in epithelium-denuded preparations in the presence of thiorphan. The contractile response to capsaicin was significantly inhibited in tissues exposed to a consecutive dose of capsaicin. Furthermore, ruthenium red abolished capsaicin-induced contraction in epithelium-denuded preparations. 5 Tissue content of calcitonin gene-related peptide-like immunoreactivity and substance P-like immunoreactivity was not reduced in bronchus and iris obtained from capsaicin-treated rabbits, although capsaicin-induced contractile responses in rabbit bronchus obtained from animals previously treated with capsaicin were significantly reduced. Furthermore, airway responses to histamine, methacholine and electrical field stimulation in vitro, were not altered by pretreatment of rabbits in vivo for 3 days with capsaicin. 6. In conclusion, PAF-induced airways responsiveness and pulmonary cell accumulation is inhibited by in vivo capsaicin pretreatment in the rabbit, via a mechanism that may not involve depletion of sensory neuropeptides.

Histopathology and immunohistochemistry of the caecum in children with the Trichuris dysentery syndrome.

Caecal biopsy specimens from Jamaican children with the Trichuris dysentery syndrome (TDS) and age matched Jamaican controls were investigated by immunohistochemistry and by light microscopy. Biopsy specimens from all children (with TDS and controls) showed a mild to moderate increase in inflammatory cells. Except in the vicinity of the worm, where the epithelium was flattened, there was no other epithelial abnormality. Compared with controls, children with TDS had increased IgM lamina propria plasma cells and decreased intraepithelial T cells. There was also an increase in crypt epithelial cell proliferation. Lamina propria T cells (both activated and non-activated) were no more common in children with the Trichuris syndrome than controls. Epithelial cell HLA-DR and VLA-1 expression (which are increased in other colitides) were the same in both groups. Despite the presence of large worm burdens and chronic dysentery, therefore, only minor changes were seen in the caecal mucosa of children with TDS.

Microsporidia and Isospora Belli infections in humans

Microsporidial infections in humans are generally caused by four genera, Nosema, Enterocytozoon, Pleistophora , and EncephalHozoon . Infection is through ingestion of the infective spores, either from stool or urine or in tissues. These organisms have been associated with diarrhea and malabsorption, blindness, muscle weakness and contractures, and hepatitis in the liver. The host cells are damaged and often rupture with granulomatous foci in the tissues. In the intestine, there may be flattening of the villi, elongation of the crypts, and an increase in inflammatory cells in the lamina propria. Diagnosis is usually based on demonstration of the spores in tissue biopsy specimens (PAS positive granule, methenamine silver positive, Gram and acid fast variable) or the presence of polar tubules in transmission electron micrographs. Spores have not yet been demonstrated in stool; the development and use of monoclonal reagents are still experimental and not commercially available. Treatment is not well defined and very little has been done on prevention and/or control. With documented diagnosis of these infections in patients with AIDS and other immune deficiencies, the clinician needs to consider microsporidia as possible etiologtc agents of disease in all compromised patients, particularly with symptoms of diarrhea or myositis. Isospora belli is transmitted through ingestion of the infective oocysts. Symptoms may range from mild gastrointestinal symptoms to severe diarrhea. Immunosuppressed patients often present with profuse diarrhea, weakness, anorexia, and weight loss. The disease is usually sell-limiting in the immunocompetent patient. Changes range from broadening of the villus tips to a flat mucosal surface and crypt elongation. There may also be inflammatory infiltrates in the lamina propria. Diagnosis is usually made by finding the oocysts in concentrated stool material (wet preparation examination). Multiple stools are recommended and biopsy material may be positive while the stool examinations are negative. These organisms are found worldwide and are probably more common in the tropics. The drug of choice is trimethoprim-sulfamethoxazole; however, there may be side effects, particularly in patients with AIDS. Although deaths have been reported, the prognosis is usually good with early diagnosis and treatment. Good personal hygiene and proper disposal of human fecal material should help decrease this infection.

Bronchial Epithelial Inflammation in Children with Chronic Cough after Early Lower Respiratory Tract Illness

We studied the ultrastructural findings in biopsies from the main carina of seven school-aged children who had had chronic cough for at least 3 months and who all had a history of early lower respiratory illness (LRI). They had their first LRI between birth and 7 yr of age (range, 5 to 11 yr). The cross-sectional area of the epithelium was quantified by point counting for the percentage area of intercellular spaces (ICS) denoting edema, and the numbers of both inflammatory cells (leukocytes, including eosinophils, and mast cells) and ciliated cells. The children (excluding the one using inhaled steroids) demonstrated nearly 17- and more than sevenfold increases in the mean area of ICS and number of inflammatory cells per epithelial area, respectively, and a nearly three-fold decrease in the mean number of ciliated cells per epithelial area compared with the biopsy specimens from the orifice of the right upper lobe bronchus of two healthy adults. In the children, the increase in inflammatory cells (greater than 91% were lymphocytes) was more prominent in the children with two LRI before the age of 1 yr. Our findings imply a close association of early LRI and later epithelial inflammation during chronic cough. Allergic mechanisms in the epithelial inflammation cannot be ruled out as six of the patients had, either alone or in combination, signs of atopia, positive family history of allergic rhinitis or asthma, and eosinophils or mast cells in the epithelium.(ABSTRACT TRUNCATED AT 250 WORDS)

Response of rodents to inhaled diluted diesel exhaust: Biochemical and cytological changes in bronchoalveolar lavage fluid and in lung tissue

The effect of long-term (24 months) inhalation of diesel exhaust on the bronchoalveolar region of the respiratory tract of rodents was assessed by serial (every 6 months) analysis of bronchoalveolar lavage fluid (BALF) and of lung tissue from F344/Crl rats and CD-1 mice (both sexes) exposed to diesel exhaust diluted to contain 0, 0.35, 3.5, or 7.0 mg soot/m 3. The purpose of the study was twofold. One was to assess the potential health effects of inhaling diluted exhaust from light-duty diesel engines. The second was to determine the usefulness of BALF analysis in detecting the early stages in the development of nononcogenic lung disease and differentiating them from the normal repair processes. No biochemical or cytological changes in BALF or in lung tissue were noted in either species exposed to the lowest, and most environmentally relevant, concentration of diesel exhaust. In the two higher levels of exposure, a chronic inflammatory response was measured in both species by dose-dependent increases in inflammatory cells, cytoplasmic and lysosomal enzymes, and protein in BALF. Histologically, after 1 year of exposure, the rats had developed focal areas of fibrosis associated with the deposits of soot, while the mice, despite a higher lung burden of soot than the rats, had only a fine fibrillar thickening of an occasional alveolar septa in the high-level exposure group. Higher increases in BALF β-glucuronidase activity and in hydroxyproline content accompanied the greater degree of fibrosis in the rat. BALF levels of glutathione (GSH) and glutathione reductase activity increased in a dose-dependent fashion and were higher in mice than in rats. Lung tissue GSH was depleted in a dose-dependent fashion in rats but was slightly increased in mice. This depletion may have played a role in the greater fibrogenic response observed in rats. Other tissue changes in enzymatic activity were small compared to changes observed in BALF. The exposure did not increase the cytochrome P-450 content of the lung in either species. The results suggest that, for the noncarcinogenic health effects reported in this paper, there is a threshold of exposure below which adverse effects were not observed. This threshold was well above environmentally relevant levels of diesel exhaust but may be in the range of some occupational exposures. The analysis of BALF proved a useful adjunct to the chronic toxicity study to quantitate the inflammatory changes accompanying the development of pulmonary disease.

Response of Rodents to Inhaled Diluted Diesel Exhaust: Biochemical and Cytological Changes in Bronchoalveolar Lavage Fluid and in Lung Tissue

Response of Rodents to Inhaled Diluted Diesel Exhaust: Biochemical and Cytological Changes in Bronchoalveolar Lavage Fluid and in Lung Tissue. HENDERSON, R. F., PICKRELL, J. A., JONES, R. K., SUN, J. D., BENSON, J. M., MAUDERLY, J. L., AND MCCLELLAN, R. O. (1988). Fundam. Appl. Toxicol . 11, 546-567. The effect of long-term (24 months) inhalation of diesel exhaust on the bronchoalveolar region of the respiratory tract of rodents was assessed by serial (every 6 months) analysis of bronchoalveolar lavage fluid (BALF) and of lung tissue from F344/Crl rats and CD-I mice (both sexes) exposed to diesel exhaust diluted to contain 0, 0.35, 3.5, or 7.0 mg soot/m 3 . The purpose of the study was twofold. One was to assess the potential health effects of inhaling diluted exhaust from light-duty diesel engines. The second was to determine the usefulness of BALF analysis in detecting the early stages in the development ofnonon-cogenic lung disease and differentiating them from the normal repair processes. No biochemical or cytological changes in BALF or in lung tissue were noted in either species exposed to the lowest, and most environmentally relevant, concentration of diesel exhaust. In the two higher levels of exposure, a chronic inflammatory response was measured in both species by dose-dependent increases in inflammatory cells, cytoplasmic and lysosomal enzymes, and protein in BALF. Histologically, after 1 year of exposure, the rats had developed focal areas of fibrosis associated with the deposits of soot, while the mice, despite a higher lung burden of soot than the rats, had only a fine fibrillar thickening of an occasional alveolar septa in the high-level exposure group. Higher increases in BALF β-glucuronidase activity and in hydroxyproline content accompanied the greater degree of fibrosis in the rat BALF levels of glutathione (GSH) and glutathione reductase activity increased in a dose-dependent fashion and were higher in mice than in rats. Lung tissue GSH was depleted in a dose-dependent fashion in rats but was slightly increased in mice. This depletion may have played a role in the greater fibrogenic response observed in rats. Other tissue changes in enzymatic activity were small compared to changes observed in BALF. The exposure did not increase the cytochrome P-450 content of the lung in either species. The results suggest that, for the noncarcinogenic health effects reported in this paper, there is a threshold of exposure below which adverse effects were not observed. This threshold was well above environmentally relevant levels of diesel exhaust but may be in the range of some occupational exposures. The analysis of BALF proved a useful adjunct to the chronic toxicity study to quantitate the inflammatory changes accompanying the development of pulmonary disease.

Pulmonary clearance of Mycoplasma pulmonis in C57BL/6N and C3H/HeN mice.

In C57BL/6N and C3H/HeN mice known to be free of all murine pathogens and matched for age, sex, and environmental factors, pulmonary clearance was measured over a 72-h time period after exposure to infectious aerosols of 35S-labeled Mycoplasma pulmonis. Reduced clearance of M. pulmonis in C3H/HeN mice relative to C57BL/6N mice was primarily due to impaired mycoplasmacidal activity in the lungs of the C3H/HeN mice. The C3H/HeN mice also had a slightly slower rate of mechanical transport of radiolabel from the lungs in the first 4 h after infection relative to the C57BL/6N mice but not at any later times. By 72 h after infection (relative to 0 h, C3H/HeN mice had an over 4,000% (1.75 X 10(7) versus 4.30 X 10(5] increase in neutrophils and an over 18,000% (more than 2 orders of magnitude) increase in numbers of M. pulmonis recovered from mechanically disaggregated lungs. In contrast, C57BL/6N mice reduced the number of M. pulmonis present by over 83% (nearly 2 orders of magnitude) before any increase in inflammatory cells, which was only a slight increase in lymphocytes and macrophages at 24 h after infection. These results directly link decreased mycoplasmal pulmonary clearance in C3H/HeN mice with the increased susceptibility to, and severity of, murine respiratory mycoplasmosis observed in this strain. The resistance of C57BL/6N mice appears to be related to nonspecific host defense mechanisms responsible for limiting the extent of infection.

Role of inflammation and inflammatory mediators in airways disease

Recent evidence suggests that airway inflammation is linked to hyper-responsiveness of airway smooth muscle. Increases in airway responsiveness after many stimuli are accompanied by increases in inflammatory cells in bronchoalveolar lavage fluid and in the airway epithelium. Airway epithelial cells may themselves be an important source of inflammatory mediators, producing metabolites that can cause chemotaxis of neutrophils and that can selectively activate other cells in the lungs. Mast cells produce a variety of enzymes and vasoactive, chemotactic, and bronchoconstrictor substances in response to non-immunologic as well as immunologic stimuli. The secretory profile of a mast cell may depend upon the specific stimulus applied. In addition, different populations of mast cells exist and distinct enzymatic pathways may predominate in different cell types. Mediators released by these cells may activate target cells by direct or indirect mechanisms. These inflammatory mediators, together with inflammatory cells, are important in the complex interactions involving airway epithelial cells, neutrophils, mast cells, smooth muscle, respiratory secretory cells, and nerves, which, in concert, are responsible for the pathophysiologic manifestations of obstructive lung disease.

INTESTINAL MAST CELLS AND NURTROPHIL CHEMOTACTIC ACTIVITY OF SERUM FOLLOWING A SINGLE CHALLENGE WITH GLUTEN IN COELIAC CHILDREN /CD/ ON GLUTEN-DIET

The purpose of our study was to investigate the number of mast cells, intraepithelial lymphocytes /IEL/ and other inflammatory cells in the intestine of 14 children with treated coeliac disease following a single challenge with gluten at 5 hours. We examined the neutrophil chemotactic activity of sera obtained at 0, 1, 3, 5 and 24 hours after challenge. There was no significant change in the number of IEL, but the biopsy specimen obtained at 5 hours showed marked increase in inflammatory cells of lamina propria and a significant decrease in the number of mast cells /87± 26 cells/mm2 mucosa in the controlls, 32,3± 10, 5 cells/mm2 after challenge/. The chemotactic activity of sera showed a significant inrease between 1-5 hours after challenge in 10 out of 14 patients. Serum neutrophil chemotactic activity was measured by a modified Boyden-chamber. These findings suggest that degranulation of mast cells may be involved in the pathogenesis of the CD.

Histopathology of Meibomian Gland Dysfunction

We conducted a histopathologic study of he meibomian glands of seven patients (all men, ranging in age from 58 to 83 years) who had severe or moderately severe meibomian dysfunction and who were undergoing ectropion or entropion repair. Abnormal features included signs of obstruction and dilatation of ducts, enlargement of acini with cystic degeneration and squamous metaplasia, foreign-body reaction and granuloma formation, a mild increase in inflammatory cells, and abnormal keratinization. Demodex organisms were found in both acini and ducts of one patient. These findings were similar to those reported in other entities involving meibomian duct obstruction, probably related to abnormalities of keratinization, plays an important role in the pathogenesis of meibomian gland dysfunction.