A case series describing common radiographic and pathologic patterns of hard metal pneumoconiosis.

INTRODUCTION: Hard metal pneumoconiosis is a rare but serious disease of the lungs associated with inhalational exposure to tungsten or cobalt dust. Little is known about the radiologic and pathologic characteristics of this disease and the efficacy of treating with immunosuppression. OBJECTIVE: We describe the largest cohort of patients with hard metal pneumoconiosis in the literature, including radiographic and pathologic patterns as well as treatment options. METHODS: We retrospectively identified patients from the University of Pittsburgh pathology registry between the years of 1985 and 2016. Experts in chest radiology and pulmonary pathology reviewed the cases for radiologic and pathologic patterns. RESULTS: We identified 23 patients with a pathologic pattern of hard metal pneumoconiosis. The most common radiographic findings were ground glass opacities (93%) and small nodules (64%). Of 20 surgical biopsies, 17 (85%) showed features of giant cell interstitial pneumonia. Most patients received systemic corticosteroids and/or steroid-sparing immunosuppression. CONCLUSIONS: Hard metal pneumoconiosis is characterized predominately by radiographic ground glass opacities and giant cell interstitial pneumonia on histopathology. Systemic corticosteroids and steroid-sparing immunosuppression are common treatment options.

Multiple flow rates measurement of exhaled nitric oxide in patients with sarcoidosis: a pilot feasibility study.

Fraction of end tidal exhaled nitric oxide (FeNO) has been introduced as a non-invasive marker of airway inflammation in patients with asthma and may have value in monitoring disease activity in patients with sarcoidosis. This pilot study explored: 1) feasibility of the multiple flow rates maneuver to estimate alveolar (C(AlV)NO) and airway wall (J(AW)NO) NO in patients with sarcoidosis; and 2) utility of exhaled NO (FeNO, C(Alv)NO and J(AW)NO) measurements to detect and monitor treatment response in patients with active pulmonary sarcoidosis. Patients with sarcoidosis (n = 42) and healthy non-smokers (n = 20) underwent FeNO measurement at 7 flow-rates (50 to 400 ml/s). Using the Tsoukias and George (1998) model, C(Alv)NO and J(AW)NO were estimated. Both patients and healthy non-smokers were able to perform the multiple flow rates maneuver without discomfort, with first measurement success rate of 57% and 65%, respectively. No significant difference was found between patients with sarcoidosis and healthy non-smokers in exhaled NO. None were correlated with pulmonary function tests, except a significant negative correlation between C(Alv)NO and FVC% (p = 0.001) and DLCO% (p = 0.012). In 8 patients with active sarcoidosis, FeNO, C(Alv)NO or J(AW)NO were not different from those of patients with inactive sarcoidosis. Treatment of active sarcoidosis using oral prednisone and methotrexate did not show any consistent pattern of changes in C(Alv)NO or J(AW)NO. Due to a large inter-subject variability and difficulty controlling use of the inhaled corticosteroids, exhaled NO measurement did not appear to be a clinically useful method of monitoring disease progression in sarcoidosis.

Increased nitric oxide production by airway cells of sensitized and challenged IL-10 knockout mice.

The anti-inflammatory cytokine interleukin (IL)-10 suppresses inducible nitric oxide synthase (iNOS); therefore, NO production should increase in the absence of IL-10. Production of NO (as nitrite) by bronchoalveolar lavage cells of IL-10 knockout ((-/-)) mice was assessed after ovalbumin sensitization and airway challenge (S/C) and was compared with the IL-10-sufficient, wild-type (WT) C57Bl6. Eosinophil recruitment occurred in S/C WT and IL-10(-/-) mice, suggesting allergic airway inflammation. Alveolar macrophages (per g mouse) were unchanged (approximately 3x10(4) cells) with the exception of a doubling in the S/C IL-10(-/-) mice (approximately 6x10(4) cells, P<0.05). NO production (per million cells) was doubled in cells from S/C IL-10(-/-) (15.3 microM) mice compared with WT (7.6 microM, P<0.05). Inhibition of iNOS by L-N(5)-(1-iminoethyl)-ornithine reduced NO production in all S/C mice, confirming that the increase was a result of up-regulation of iNOS. We conclude that IL-10 is a critical cytokine regulating iNOS in murine airway cells and that its absence can lead to up-regulation of iNOS and development of allergic airway inflammation.

Nitric oxide suppresses the expression of Bcl-2 binding protein BNIP3 in hepatocytes.

Nitric oxide (NO) is not only an important signaling molecule, but it also regulates the expression of a number of genes in the liver. We have previously shown that apoptosis in hepatocytes exposed to tumor necrosis factor-alpha and actinomycin D is prevented by NO derived from the inducible nitric-oxide synthase (iNOS), by mechanisms that are both dependent on and independent of modulation of cyclic guanosine monophosphate (cGMP) subsequent to activation of soluble guanylyl cyclase (sGC). We hypothesize that one mechanism by which NO exerts these effects is by regulating the expression of genes involved in apoptosis. We used differential display-polymerase chain reaction to isolate NO-regulated genes in hepatocytes from iNOS knockout mice (to eliminate endogenous inducible NO production). Using this analysis, we identified a NO-suppressed gene fragment homologous with the pro-apoptotic Bcl-2 binding protein BNIP3. Northern analysis confirmed the NO-dependent suppression of BNIP3 in cultured cells. Similarly, the NO donor S-nitroso-N-acetyl-dl-penicillamine (1-1000 microm) down-regulated the expression of BNIP3 in both iNOS knockout and wild-type hepatocytes. This effect of NO was reversed by the sGC inhibitor 1H-(1,2,4)-oxadiazole[4,3-a]quinoxalon-1-one (ODQ),suggesting the involvement of the sGC/cGMP pathway in the modulation of BNIP3 by NO. We propose that suppression of BNIP3 expression is one sGC/cGMP-dependent mechanism by which NO might affect the process of hepatocyte apoptosis.

Nitric oxide from the inducible nitric oxide synthase (iNOS) increases the expression of cytochrome P450 2E1 in iNOS-null hepatocytes in the absence of inflammatory stimuli.

Nitric oxide (NO) can modulate numerous genes through several pathways, yet some genes may be modulated only in the presence of the inflammatory stimuli that upregulate the inducible nitric oxide synthase (iNOS) rather than by NO alone. Furthermore, the role of prior expression of iNOS in the modulation of genes by NO is unknown. We addressed these issues in hepatocytes harvested from iNOS-null (iNOS(-/-)) mice exposed to NO by treatment with NO donors or by infection with an adenovirus-expressing human iNOS (Ad-iNOS), rather than by stimulation with inflammatory cytokines. Differential display and gene array analyses performed on mRNA derived from iNOS(-/-) hepatocytes demonstrated that infection with Ad-iNOS, but not infection with a control adenovirus expressing the beta-galactosidase gene (Ad-LacZ), induced a gene fragment identical to cytochrome P450 2E1 (CYP2E1). Northern analysis performed with this fragment demonstrated that treatment of iNOS(-/-) hepatocytes with Ad-iNOS or with the NO donor S-nitroso-N-acetyl-d,l-penicillamine (SNAP), but not control treatment or infection with Ad-LacZ, resulted in increased expression of CYP2E1. Inhibition of soluble guanylyl cyclase partially blocked the induction of CYP2E1 mRNA by Ad-iNOS. Rat hepatocytes treated with SNAP also exhibited increased expression of CYP2E1 mRNA. Preliminary studies, however, suggest that the induction of CYP2E1 in the rat hepatocytes treated with cytokines was not reduced in the presence of a NOS inhibitor. Our results suggest that CYP2E1 can be induced solely by NO derived from iNOS, at least partly in a cyclic GMP-dependent manner and independently of inflammatory stimuli or of prior exposure to NO.

Actin-containing sera from patients with adult respiratory distress syndrome are toxic to sheep pulmonary endothelial cells.

Actin released from damaged cells after a variety of tissue injuries appears to be involved in multiple organ dysfunction syndrome. Under experimental conditions, when the quantity of actin present in plasma is made to exceed the protective capacity of the actin-scavenging mechanism, microembolism and pulmonary vascular angiopathy have been noted in rats. It remains to be determined whether this injury is a result of a direct toxic effect or occurs indirectly via platelet activation or fibrin interactions. We examined the effect of sera from patients with adult respiratory distress syndrome (ARDS), as well as G-actin added to normal serum, on the viability, morphology, and function of cultured sheep pulmonary artery endothelial cells (SPAEC). Both patient sera and normal sera to which actin was added were toxic in the cell culture model; this toxicity could be abrogated, at least partially, by preincubation with gelsolin, which is known to complex with actin. A significant portion of the toxicity of sera from patients with ARDS was sensitive to heat (56 degrees C), suggesting an important role of complement. Sera from patients with ARDS were shown to contain filaments of F-actin by immunoblot and rhodamine phalloidin staining after ultracentrifugation. Thus, saturation of the actin-scavenging system by addition of exogenous G-actin to plasma produces direct pulmonary endothelial cell injury. Furthermore, plasma from patients with ARDS secondary to bacterial pneumonia is toxic to SPAEC, and a small but significant contributory role of actin is apparent in these studies.

Intracellular distribution of lysozyme in rat alveolar type II epithelial cells.

This study investigated the intracellular distribution of lysozyme, a protein that is synthesized and secreted by rat alveolar type II epithelial (ATII) cells and alveolar macrophages, using a polyclonal antibody generated against purified rat lysozyme. Lysozyme was immunoprecipitated with this antibody from Triton X-100 lysates of ATII cells cultured on a basement membrane derived from Englebreth-Holme-Swarm mouse sarcoma (EHS) and radiolabeled with 35S-methionine. ATII cells cultured on EHS basement membrane for several days were fixed and labeled with antibodies to surfactant apoprotein A (SP-A) and lgp-120 (a lysosomal glycoprotein), or lysozyme and lgp-120, and studied by confocal microscopy. Organelles were identified that stained positively for either anti-lysozyme or anti-lgp-120; a second population of organelles contained both markers. Similarly, two populations of SP-A-containing organelles were identified; one contained the lysosomal glycoprotein lgp-120. In addition, confocal images demonstrated that both SP-A and lysozyme were secreted by ATII cells, as evidenced by the accumulation of secretory products within the lumen of the cyst-like aggregates. When the subcellular localization of SP-A and lysozyme was studied by analytical cell fractionation, two populations of organelles were identified that contained SP-A or lysozyme. The lighter population accounted for approximately 32% of SP-A and 33% of total intracellular lysozyme and was recovered in the same region of the gradient as secretory lamellar bodies. The more dense population co-localized with lysosomes and accounted for approximately 67% of both SP-A and lysozyme recovered. Western blots of cell fractions revealed intact lysozyme in all the cell fractions. The results of these experiments suggest that lysozyme has a similar intracellular distribution as surfactant apoprotein A in ATII cells. Lysozyme is found in fractions containing lamellar bodies where it is packaged for secretion, and in lysosomal fractions where it may undergo degradation.

Procainamide-induced myasthenia-like weakness and dysphagia.

A 64-year-old man with chronic renal insufficiency was hospitalized with dysphagia and inability to keep his head erect 11 months after beginning procainamide hydrochloride (PA) for control of atrial flutter. Evaluation revealed esophageal dysmotility, worsening renal function, and elevated serum PA and N-acetylprocainamide (NAPA) concentrations. No evidence of autoimmune myasthenia gravis was found. PA was discontinued and normalization of PA and NAPA concentrations was associated with a decrease in muscle weakness and resolution of dysphagia. The correlation between clinical findings and serum concentrations of PA and NAPA suggests that drug excess due to impaired clearance was the basis for this unusual adverse drug reaction.

Lasers in medicine--a review.

Laser systems permit very high energy radiation of a single wavelength to be focused on a tiny spot, and have found application in many areas of engineering. They are also currently used in many branches of medicine. The fields reviewed here are ophthalmology, gynaecology, dermatology, otolaryngology, gastroenterology and physiotherapy. Lasers which are in wide use for medical applications include argon, YAG and carbon dioxide types. In many areas, lasers have been found to be more effective than conventional treatment methods with advantages including less blood loss, more accurate removal of unwanted tissue, shorter operating time and less postoperative pain. It is expected that the next decade will see the laser as an everyday tool in many more medical applications.

The relationship between lamellar bodies and lysosomes in type II pneumocytes.

We have studied the relationship between lysosomes and lamellar bodies in alveolar type II (ATII) pneumocytes using a monoclonal antibody (anti-lgp-120) directed against a 120-kD rat lysosomal membrane glycoprotein and a polyclonal antibody (anti-SP-A) directed against rat surfactant protein A. The anti-lgp-120 precipitated a protein molecular mass of 120 kD from Triton cell lysates radiolabeled with [35S]methionine, and the anti-SP-A precipitated surfactant apoprotein A from the medium when analyzed under similar conditions. When ATII cells were cultured on Engelbreth-Holm-Swarm tumor basement membrane, and studied by indirect immunofluorescence, some structures seem to react with both antibodies, and others with only one. ATII cells cultured on plastic showed a major population of large vesicles that were labeled intensely with both antibodies, and a second population of vesicles that were labeled weakly and only with anti-SP-A. Analytical cell fractionation of freshly isolated ATII cells confirmed that lgp-120 was only present in structures containing the lysosomal matrix enzyme N-acetyl-beta-glucosaminidase. In contrast, SP-A was identified in two populations of vesicles with high phospholipid-to-protein ratios: one lacked N-acetyl-beta-glucosaminidase and lgp-120 and contained lamellar bodies; the other contained both lysosomal markers and a heterogeneous population of organelles that included multivesicular bodies, lamellar bodies, and lysosomes. Western blots of trichloroacetic acid precipitates of cell fractions identified proteins within the lysosomal compartment that reacted with anti-SP-A, but whose molecular mass was less than 28 kD. The results indicate that, in ATII cells, surfactant is located in two functionally distinct structures, one of which is probably involved in surfactant secretion, and the other, surfactant degradation. The techniques developed in this study should allow the role of these structures in the secretion and recycling of surfactant to be determined.