Evaluation of the Pulmonary Toxicity of Ambient Particulate Matter From Camp Victory, Iraq

Anecdotal reports in the press and epidemiological studies suggest that deployment to Iraq and Afghanistan may be associated with respiratory diseases and symptoms in U.S. military personnel and veterans. Exposures during military operations were complex, but virtually all service members were exposed to high levels of respirable, geogenic dust. Inhalation of other dusts has been shown to be associated with adverse health effects, but the pulmonary toxicity of ambient dust from Iraq has not been previously studied. The relative toxicity of Camp Victory dust was evaluated by comparing it to particulate matter from northern Kuwait, a standard U.S. urban dust, and crystalline silica using a single intratracheal instillation in rats. Lung histology, protein levels, and cell counts were evaluated in the bronchoalveolar lavage fluid 1-150 d later. The Iraq dust provoked an early significant, acute inflammatory response. However, the level of inflammation in response to the Iraq dust, U.S. urban dust, and Kuwait dust rapidly declined and was nearly at control levels by the end of the study At later times, animals exposed to the Iraq, U.S. urban, or Kuwait dusts showed increased small airway remodeling and emphysema compared to silica-exposed and control animals without evidence of fibrosis or premalignant changes. The severity and persistence of pulmonary toxicity of these three dusts from the Middle East resemble those of a U.S. urban dust and are less than those of silica. Therefore, Iraq dust exposure is not highly toxic, but similar to other poorly soluble low-toxicity dusts.

Myocardial Mechanisms Causing Heart Failure Early After Cardiac Transplantation

Early after heart transplantation, some patients have heart failure (HF) with preserved left ventricular ejection fraction (LVEF), in the absence of rejection. The purpose of this study was to define the mechanisms causing HF early after transplantation and to determine whether these mechanisms involve changes that occur in active or passive myocardial properties. Eleven consecutive patients 1 week after heart transplantation underwent right heart catheterization and echocardiography with an endomyocardial biopsy. Hemodynamic measurements were obtained at spontaneous heart rate, and then were repeated at three atrially paced rates increased in 20-bpm increments above spontaneous heart rate. At baseline, 5 patients (group 1) had clinical HF and a pulmonary capillary wedge pressure (PCWP) > or = 16 mmHg, and 6 patients (group 2) had no clinical evidence of HF and a PCWP < 16 mmHg. LVEF was normal in all 11 patients. The relationships between cardiac index versus heart rate (HR) and PCWP versus HR were normal in all 11 patients. These normal function-versus-frequency relationships suggested that there were no significant abnormalities in the active myocardial processes of contraction or relaxation. In group 1 patients, the PCWP was significantly increased but the left ventricular end diastolic dimension was normal, suggestive of diastolic stiffness. Early after transplantation, there was a significant increase in LV wall thickness in group 1 patients as compared with preexplantation values despite myocardial biopsies in all 11 patients, showing no evidence of rejection, cardiomyocyte hypertrophy, or interstitial fibrosis thus suggestive of myocardial edema.

Myofibroblast induction and microvascular alteration in scleroderma lung fibrosis

OBJECTIVE

Scleroderma (SSc) is an autoimmune connective tissue disorder characterized by progressive fibrosis of the skin and internal organs. The leading cause of death in SSc patients is pulmonary dysfunction as a result of interstitial fibrosis and pulmonary vasculopathy. Our objective was to evaluate histopathological abnormalities associated with the development of pulmonary fibrosis in SSc.

METHODS

Postmortem SSc lung tissue from various stages of fibrosis and tissue from normal lung were analyzed by Masson's trichrome staining and immunohistochemistry. Monoclonal antibodies against smooth muscle-alpha actin (myofibroblast marker), von Willebrand Factor, platelet endothelial cell adhesion molecule-1 (endothelial cell markers), or caldesmon (smooth muscle cell marker) were employed.

RESULTS

We found that in the early active stages of SSc lung fibrosis two major types of cellular abnormalities occur. One is the induction of a large number of smooth muscle alpha-actin-positive myofibroblasts in interstitia. The other is the excessive formation of alveolar capillaries (hypervascularity) accompanied by an increase in the number of microvascular endothelial cells. The vascular abnormality also involves the development of microvessels that are irregular in size and shape. However, the population of myofibroblasts and capillary endothelial cells decline as the fibrosis progresses to its most marked, later stages.

CONCLUSION

We conclude that the induction of myofibroblasts and the overdevelopment of capillary microvessels characterize the progression of lung fibrosis in SSc. Using these histological alterations as criteria, therefore we have divided the fibrosis formed in the SSc lungs into four pathological stages. These results suggest that both fibroblast overproliferation and vascular abnormality play an important role in the pathogenesis of lung fibrosis in SSc.

Separation of fine particulate matter emitted from gasoline and diesel vehicles using chemical mass balancing techniques

Samples of fine particulate matter were collected in a roadway tunnel near Houston, TX over a period of 4 days during two separate sampling periods: one sampling period from 1200 to 1400 local time and another sampling period from 1600 to 1800 local time. During the two sampling periods, the tunnel traffic contained roughly equivalent numbers of heavy-duty diesel trucks. However, during the late afternoon sampling period, the tunnel contained twice as many light-duty gasoline-powered vehicles. The effect of this shift in the vehicle fleet affects the overall emission index (grams pollutant emitted per kilogram carbon in fuel) for fine particles and fine particulate elemental carbon. Additionally, this shift in the fraction of diesel vehicles in the tunnel is used to determine if the chemical mass balancing techniques used to track emissions from gasoline-powered and diesel-powered emissions accurately separates these two emission categories. The results show that the chemical mass balancing calculations apportion roughly equal amounts of the particulate matter measured to diesel vehicles between the two periods and attribute almost twice as much particulate matter in the late afternoon sampling period to gasoline vehicles. Both of these results are consistent with the traffic volume of gasoline and diesel vehicles in the tunnel in the two separate periods and validate the ability for chemical mass balancing techniques to separate these two primary sources of fine particles.

On-road measurement of carbonyls in California light-duty vehicle emissions

Emissions of carbonyls by motor vehicles are of concern because these species can be hazardous to human health and highly reactive in the atmosphere. The objective of this research was to measure carbonyl emission factors for California light-duty motor vehicles. Measurements were made at the entrance and exit of a San Francisco Bay area highway tunnel, in the center bore where heavy-duty trucks are not allowed. During summer 1999, approximately 100 carbonyls were identified, including saturated aliphatic aldehydes and ketones, unsaturated aliphatic carbonyls, aliphatic dicarbonyls, and aromatic carbonyls. Concentrations were measured for 32 carbonyls and were combined with NMOC, CO, and CO2 concentrations to calculate by carbon balance emission factors per unit of fuel burned. The measured carbonyl mass emitted from light-duty vehicles was 68 +/- 4 mg L(-1). Formaldehyde accounted for 45% of the measured mass emissions, acetaldehyde 12%, tolualdehydes 10%, benzaldehyde 7.2%, and acetone 5.9%. The ozone forming potential of the carbonyl emissions was dominated by formaldehyde (70%) and acetaldehyde (14%). Between 1994 and 1999, emission factors measured at the same tunnel for formaldehyde, acetaldehyde, and benzaldehyde decreased by 45-70%. Carbonyls constituted 3.9% of total NMOC mass emissions and 5.2% of NMOC reactivity. A comparison of carbonyl emissions with gasoline composition supports previous findings that aromatic aldehyde emissions are related to aromatics in gasoline. Carbonyl concentrations in liquid gasoline were also measured. Acetone and MEK were the most abundant carbonyls in unburned gasoline; eight other carbonyls were detected and quantified.

A fuel-based assessment of off-road diesel engine emissions

The use of diesel engines in off-road applications is a significant source of nitrogen oxides (NOx) and particulate matter (PM10). Such off-road applications include railroad locomotives, marine vessels, and equipment used for agriculture, construction, logging, and mining. Emissions from these sources are only beginning to be controlled. Due to the large number of these engines and their wide range of applications, total activity and emissions from these sources are uncertain. A method for estimating the emissions from off-road diesel engines based on the quantity of diesel fuel consumed is presented. Emission factors are normalized by fuel consumption, and total activity is estimated by the total fuel consumed. Total exhaust emissions from off-road diesel equipment (excluding locomotives and marine vessels) in the United States during 1996 have been estimated to be 1.2 x 10(9) kg NOx and 1.2 x 10(8) kg PM10. Emissions estimates published by the U.S. Environmental Protection Agency are 2.3 times higher for both NOx and exhaust PM10 emissions than estimates based directly on fuel consumption. These emissions estimates disagree mainly due to differences in activity estimates, rather than to differences in the emission factors. All current emission inventories for off-road engines are uncertain because of the limited in-use emissions testing that has been performed on these engines. Regional- and state-level breakdowns in diesel fuel consumption by off-road mobile sources are also presented. Taken together with on-road measurements of diesel engine emissions, results of this study suggest that in 1996, off-road diesel equipment (including agriculture, construction, logging, and mining equipment, but not locomotives or marine vessels) was responsible for 10% of mobile source NOx emissions nationally, whereas on-road diesel vehicles contributed 33%.

Localization and expression of tissue kallikrein and kallistatin in human blood vessels

Tissue kallikrein releases kinins by specific proteolysis, an activity inhibited by kallistatin. In this study, kallikrein and kallistatin were localized to endothelial and smooth muscle cells of large, medium, and small normal blood vessels by immunohistochemical techniques. Immunostaining for both proteins was strong in the endothelium of all sizes of blood vessels and was more intense in medial smooth muscle cells of small and medium-sized blood vessels than in elastic arteries. The sites of synthesis by endothelial and smooth muscle cells were demonstrated in normal blood vessels of all sizes by in situ hybridization histochemistry. Kallikrein and kallistatin levels were measured by immunoassays in homogenates of human aorta, vena cava, and iliac artery and vein. Tissue kallikrein and kallistatin transcripts were identified in human blood vessels by RT-PCR followed by Southern blot analysis with specific oligonucleotide probes. The results demonstrated the expression and co-localization of tissue kallikrein and kallistatin in human vessels and suggest a potential role of kallistatin in regulating tissue kallikrein in blood vessels.

Cellular localization of kallistatin and tissue kallikrein in human pancreas and salivary glands

The tissue kallikrein-kinin system contributes to the regulation of local blood flow, vascular permeability, inflammatory responses, and ion transport. Tissue kallikrein is a serine proteinase which produces vasoactive kinin peptides. Kallistatin specifically binds to tissue kallikrein and inhibits its proteolytic activity. To investigate their anatomical relationship in the human pancreas and salivary glands, the expression and localization of kallistatin and tissue kallikrein were identified by immunoassays, immunohistochemistry, and in situ hybridization histochemistry. Human kallistatin and tissue kallikrein levels were measured by ELISA and radioimmunoassay, respectively, in pancreatic and salivary tissue extracts, and in pancreatic fluid and saliva. Immunoreactive kallistatin and kallikrein were colocalized in acinar cells of the human pancreas by immunohistochemistry. In situ hybridization histochemistry confirmed the presence of both mRNAs in pancreatic acini. In salivary glands, kallistatin and kallikrein mRNAs were also colocalized in serous acinar cells, and the kallikrein transcript was further localized to striated and interlobular ducts. Immunoreactive kallistatin was localized in serous acinar and demilune cells of salivary glands and kallikrein was localized to the epithelium of striated and interlobular ducts. The colocalization and/or coexpression of human tissue kallikrein and kallistatin in the pancreas and salivary glands suggest a role for kallistatin in the regulation of tissue kallikrein in these organs.

Reducing the risk of accidental death due to vehicle-related carbon monoxide poisoning

Emissions of carbon monoxide (CO) from motor vehicles cause several hundred accidental fatal poisonings annually in the United States. The circumstances that could lead to fatal poisonings in residential settings with motor vehicles as the source of CO were explored. The risk of death in a garage (volume = 90 m3) and a single-family dwelling (400 m3) was evaluated using a Monte Carlo simulation with varying CO emission rates and ventilation rates. Information on emission rates was obtained from a survey of motor vehicle exhaust gas composition under warm idle conditions in California, and information on ventilation rates was obtained from a summary of published measurements in the U.S. housing stock. The risk of death ranged from 16 to 21% for a 3-hr exposure in a garage to 0% for a 1-hr exposure in a house. Older vehicles were associated with a disproportionately high risk of death. Removing all pre-1975 vehicles from the fleet would reduce the risk of death by one-fourth to two-thirds, depending on the exposure scenario. Significant efforts have been made to control CO emissions from motor vehicles with the goal of reducing CO concentrations in outdoor air. Substantial public health benefit could also be obtained if vehicle control measures were designed to take account of acute CO poisonings explicitly.

Respiratory reovirus 1/L induction of intraluminal fibrosis. A model for the study of bronchiolitis obliterans organizing pneumonia

Bronchiolitis obliterans organizing pneumonia (BOOP) is a term that was first applied in 1985 to describe a long-observed but unclassified pattern of acute lung injury. BOOP lesions are characterized by fibrous extensions into the alveolar spaces in association with a peribronchiolar organizing pneumonia. Since 1985, an increasing number of reports of BOOP have appeared in the clinical literature, and it is now accepted that BOOP is a significant pulmonary syndrome. Although BOOP can be associated with a number of documented pulmonary insults, many cases are not associated with known causes and are thus classified as idiopathic. The lack of an appropriate small animal model that closely mimics the generation of BOOP lesions has been an impediment to basic studies of the pathogenic mechanisms responsible for the generation of BOOP in humans. In this report, we describe an animal model for BOOP in which CBA/J mice infected with reovirus serotype 1/strain Lang develop BOOP lesions. These lesions closely resemble those seen in humans and occur in a well defined temporal sequence that proceeds from initial peribronchiolar inflammatory lesions to characteristic, fibrotic cellular BOOP lesions over a 3-week time course.

Fine-needle aspiration cytology of pleuropulmonary blastoma: case report and review of the literature

This report describes the fine-needle aspiration (FNA) cytology of a case of pleuropulmonary blastoma in a 3-yr-9-mo-old male. Pleuropulmonary blastoma is considered by most authors to be distinct from pulmonary blastoma and is a rare malignant tumor of the intrathoracic cavity. FNA smears were cellular with numerous small ovoid to spindled cells with oval to elliptical nuclei exhibiting finely granular chromatin and inconspicuous nucleoli. The cytoplasm was scant and eosinophilic with indistinct borders. Focal chondroid material and blastema-like cells were noted. The differential diagnosis suggested by the cytologic findings included rhabdomysosarcoma, teratoma, neuroblastoma, malignant mesenchymoma, pleuropulmonary blastoma, and metastatic tumor. To our knowledge, this is the first report of the cytology of this tumor.

Fatal disseminated herpes simplex in pregnancy with maternal and neonatal death

Disseminated herpes is rare in the adult and usually occurs in the immunocompromised. Twenty-one cases have been reported in which healthy women contracted life-threatening disseminated herpes simplex virus (HSV) infections in the third trimester of pregnancy. Most of these patients had nonspecific symptoms, and many did not have mucocutaneous lesions. On physical examination, they were usually febrile and anicteric and had markedly elevated aminotransferase values, without a corresponding elevation in bilirubin level. In our review of the literature, we found that prompt acyclovir therapy resulted in 100% survival. Those patients not receiving treatment or treated late in the terminal stages of their disease had a 63% mortality rate. We report a case of maternal disseminated HSV with subsequent maternal death at an estimated 31 weeks' gestation in which the diagnosis was made at the time of necropsy. The infant was started on acyclovir therapy but died of disseminated HSV.

Silicone deposition in reconstruction scars of women with silicone breast implants

BACKGROUND

The possible association of silicone breast implants and disease is a subject of continuous debate and concern.

OBJECTIVE

Our purpose was to examine microscopically and ultrastructurally the periprosthetic fibrous capsules and reconstruction scars of women with silicone breast implants.

METHODS

Representative samples from the periprosthetic capsules and reconstruction scars from six women with silicone breast implants were examined by a variety of light microscopy techniques, transmission electron microscopy, and electron probe microanalysis.

RESULTS

Silicone globules of various sizes were identified in every periprosthetic capsule and reconstruction scar.

CONCLUSION

Extrusion and seeding of the incision tract during surgery most likely accounts for the presence of silicone in the reconstruction scar specimens. This observation suggests that the identification of silicone in the reconstruction scars of women with silicone breast implants does not necessarily implicate rupture of the silicone breast implant with systemic dissemination of silicone gel.

Cellular localization of low-molecular-weight kininogen and bradykinin B2 receptor mRNAs in human kidney

Kininogen is the precursor of the kinin peptide, which binds to kinin receptors and mediates a broad spectrum of physiological effects. To understand the function of kinin in the kidney, we have identified the cellular localization of the human low-molecular-weight (LMW) kininogen and bradykinin B2 receptor mRNAs in the human kidney by in situ hybridization histochemistry. Kininogen mRNA was found in the juxtaglomerular cells, mesangial areas, epithelium of parietal and visceral (podocytes) layers of Bowman's capsule, proximal and distal tubules, thin and thick segments of Henle's loop, collecting ducts, and the endothelial cells of the blood vessels. B2 receptor mRNA was colocalized with kininogen mRNA in the kidney except the podocytes. The most intense signals were observed in the distal tubules and collecting ducts for both kininogen and B2 receptor mRNAs. No signals were observed in the interstitial cells and macula densa. Control sections did not stain with either the kininogen or B2 receptor sense riboprobe. A Northern blot showed that the expression of LMW kininogen is in the liver and the kidney. Reverse transcription-polymerase chain reaction Southern blot showed expression of B2 receptor mRNA in the endothelial cells, renal proximal tubular cells, and kidney. Our results show the sites of action of kinin in the human kidney and provide further insight into the physiological role of the kallikrein-kinin system on renal function.

Respiratory-mucosal lymphocyte populations induced by reovirus serotype 1 infection

Respiratory virus infections are a serious health challenge. While models exist to study immune mechanisms of the respiratory tract, they have not allowed analysis of the interaction of the lower respiratory tract with other components of the mucosal immune system. This study demonstrates that reovirus 1/Lang, an effective gut mucosal immunogen, also provides a useful model of respiratory mucosal infection. Intra-nasal infection of Balb/c mice resulted in severe viral bronchopneumonia. Major components of the cellular inflammatory response in the lung interstitium and alveolar spaces were CD8 lymphocytes. Lung lymphocyte populations exhibited lysis of reovirus-infected, but not uninfected target cells after in vitro culture. The GCT antigen, a germinal center B-cell and CD8 T-cell marker, was present on 21-60% of the inflammatory lymphocytes. A novel population of GCT-expressing CD4+ lymphocytes unique to reovirus-stimulated lung alveolar and interstitial lymphocyte populations was identified.

Mosaic vs. nonmosaic trisomy 9: report of a liveborn infant evaluated by fluorescence in situ hybridization and review of the literature

We report on a newborn infant with multiple congenital anomalies and apparent nonmosaic trisomy 9 in the blood (by conventional cytogenetic studies) who died shortly after birth. Clinical observations at birth and autopsy are compared with phenotypes of mosaic and nonmosaic trisomy 9 cases reported previously. Unlike the initial cytogenetic analysis, fluorescence in situ hybridization (FISH) studies of metaphase and interphase blood cells and skin fibroblasts detected the presence of euploid and trisomy 9 cells. These results suggest that earlier reports of trisomy 9, which relied on conventional chromosome analysis of a few metaphase cells and/or only one tissue type, may not have excluded mosaicism, and that trisomy 9 may be viable only in the mosaic state.

Experimental reovirus serotype 1/strain Lang infection of the lung: a model for the study of the lung in the context of mucosal immunity

A number of studies have examined the nature of the respiratory immune response to particular pathogens. Although many pathogens stimulate specific immunity in the lung, they frequently are not effective immunogens at other mucosal sites. Because the gastrointestinal tract is a major inductive site for mucosal immunity, a pathogen that is an effective respiratory and gut immunogen would allow studies of the interaction of the lung with gut mucosal immune system. Reovirus, a respiratory isolate that previously has been shown to be an effective gut mucosal immunogen, provides a potential model of the relationship of the lung to the gut mucosal immune system. In this report, we demonstrate that intranasal application of reovirus serotype 1/strain Lang (1/L) to CD-1 mice elicits an acute lymphocytic inflammatory infiltration of the lung and hyperplasia of the lung-associated lymph nodes. The initial inflammatory response occurs in the airspaces and interstitium of the lung. As the infection progresses, the initially diffuse cellular infiltrate becomes more focused around small bronchioles. Viral replication occurs predominantly during the first week of the infection, and infectious virions are eliminated during the second week. After the elimination of infectious virions, a secondary response consisting of the appearance of plasma cells adjacent to pulmonary arteries develops as the primary infiltrate organizes into peribronchiolar follicles, resembling the human inflammatory lung condition termed follicular bronchiolitis. These two infiltration patterns were also observed by immunohistochemical analysis of the the infected lung. Whereas CD4+ and CD8+ lymphocytes and Mac-1+ cells were found to be more closely associated with the primary infiltration process, B220+ lymphocytes were observed adjacent to pulmonary arteries. These results establish respiratory reovirus 1/L infection as a viable model for future investigations of the mucosal immune response in the lung and its relationship to the common mucosal immune system.

Talc slurry pleurodesis. Pleural fluid and histologic analysis

Although talc slurry pleurodesis is effective for control of malignant pleural effusions and recurrent pneumothorax, the mechanisms of pleurodesis remain incompletely defined. We instilled 70 mg/kg of sterile asbestos-free talc slurry into the pleural space of New Zealand white rabbits and studied the inflammatory response at 1, 2, 3, 7, 15, 30, 60, 90, and 120 days by observing pleural fluid and histologic characteristics. Talc slurry caused mesothelial denudement and an exudative neurotrophilic pleural effusion that resolved after 48 h. A transient mononuclear vasculitis was seen within the lung at 1, 2, and 3 days after instillation. Pleural adhesions were minimal and did not increase in number over time. Talc was found outside of the pleural space in mediastinal lymph nodes (4 of 23 animals examined), kidney (1 of 6), and spleen (4 of 10). The predominant cause of pleurodesis with talc slurry instillation is an acute pleural injury similar to the tetracycline class agents.

Electron probe microanalysis of silicon and the role of the macrophage in proximal (capsule) and distant sites in augmentation mammaplasty patients

Electron probe x-ray microanalysis was used to locate silicon (Si) within macrophages from 12 women who had previously undergone polymer prosthesis augmentation or reconstruction. Silicon was identified within macrophages and extracellularly in all fibrous breast capsules. In four women with arthritic joint pain and one woman with sclerodermatous skin lesions, silicon also was identified within macrophages residing in joint synovium and skin, respectively. It is suggested that the silicon-laden macrophages observed in the remote lesions may have accumulated silicon from other macrophages that had previously resided in the connective-tissue capsule around the silicone breast implants.

Immunological function in post-traumatic splenosis

A 28-year-old male medical student underwent splenectomy at 8 years of age due to traumatic rupture of the spleen sustained in a motor vehicle accident. Eighteen years later the patient had major abdominal surgery performed for an unrelated condition and, at the time of surgery, over 100 splenic nodules were found embedded throughout the patient's omentum, small bowel, and mesentery. An extensive study of immunological functions was carried out during the following 2 years. Through the course of this investigation, it was determined that the patient's peripheral blood smear lacked Howell-Jolly bodies and deformed or damaged erythrocytes, indicating that the splenotic tissue had the capacity to remove intranuclear inclusions from circulating red cells and to phagocytose old erythrocytes. The patient's levels of complement, serum immunoglobulins and the numbers of circulating T and B lymphocytes, helper T cells, and cytotoxic/suppressor T cells all were within the normal range. The response to Streptococcus pneumoniae polysaccharides was also normal, with increased levels of specific antibodies to all serotypes included in the vaccine 4 months after immunization. Finally, histological examination of his biopsied splenotic nodules revealed tissue that was indistinguishable from normal spleen.

The role of mast cells in the development of skin fibrosis in tight-skin mutant mice

Chronic inflammatory conditions can evolve a fibrotic phenotype often associated with an increase in the number of mast cells (MC) near or within the granulation tissue. Despite the potential of MC to mediate fibrosis, it is unclear whether these cells play a central role in the pathogenesis of fibrosis or whether their presence is simply circumstantial. The tight-skin (Tsk) mouse develops an inherited fibrotic disease (sharing many similarities with the human disease scleroderma, systemic sclerosis) in which the lesions are associated with increased numbers and heightened granule release implicating MC in the pathogenesis of fibrosis. Despite their close association with the skin fibrosis of Tsk mice, the precise role of the MC in the pathogenesis of this inherited disease is unknown. Therefore, to assess directly whether MC are key elements in the pathogenesis of Tsk fibrosis, we generated MC deficient mice carrying the Tsk locus by utilizing selective interbreeding between Tsk and mutant mice deficient in mast cells (W, dominant white-spotting). We found that in the absence of MC, the early natural history of Tsk fibrosis was not altered. Furthermore, in older (5-7 months) Tsk mice, we found that the number of cutaneous MC was correlated with a more pronounced fibrosis. Therefore, we conclude that Tsk skin lesions are a pleiotropic manifestation of the Tsk gene in which MC are involved/recruited by an uncharacterized mechanism and that subsequent proliferation and activation of MC leads to augmentation of fibrosis.

A murine model of the eosinophilia-myalgia syndrome induced by 1,1'-ethylidenebis (L-tryptophan)

The eosinophilia-myalgia syndrome (EMS) is a recently described disease that has been associated with the ingestion of L-tryptophan containing trace amounts of several impurities. The first such contaminant to be identified and linked epidemiologically to the EMS epidemic was 1,1'-ethylidenebis(L-tryptophan) (EBT), but its role in the etiology and pathogenesis of the syndrome has been controversial. We report the development of inflammation and fibrosis affecting the dermis and subcutis, including the fascia and perimyseal tissues, after the daily intraperitoneal administration of EBT to female C57BL/6 mice. Such changes are accompanied by increased numbers of mast cells, many of which appear to be degranulating. Plasma levels of quinolinic acid, a metabolic product of L-tryptophan via the kynurenine pathway, are reduced initially, and then become elevated when inflammation and fibrosis are more pronounced. The nature and location of the inflammatory cell infiltrate and fibrosis, as well as the presence of mast cells and alterations of L-tryptophan metabolism, are consistent with findings reported in patients with EMS. This murine model suggests that EBT may have been one of the mediators of EMS and should facilitate studies of the pathogenesis of EMS.

Primary extraosseous pulmonary osteogenic sarcoma: CT findings

This is a report of a primary extraosseous osteogenic sarcoma of the lung. The patient presented with fever and productive cough. Chest radiography and CT showed a cavitary lesion with an air-fluid level. The lesion was treated as an abscess. Despite aggressive antibiotic therapy and drainage, the patient continued to deteriorate rapidly. At autopsy the lesion was found to be a primary extraosseous pulmonary osteogenic sarcoma.

Cardiomyopathy and myocarditis in children with ventricular ectopic rhythm

OBJECTIVE

The objective of this study was to evaluate the histologic features of the myocardium in children with abnormal ventricular ectopic rhythm but a structurally normal heart.

BACKGROUND

Abnormal ventricular ectopic rhythm in children with a structurally normal heart is an uncommon but serious condition. Previous studies in adults with these findings have shown that approximately 10% have "primary electrical disease" and that 40% to 100% of these have abnormal histologic findings.

METHODS

Endomyocardial biopsy samples were obtained prospectively in 33 subjects presenting with ventricular ectopic rhythm but a structurally normal heart by physical examination and noninvasive studies. Biopsy specimens were evaluated for histologic changes consistent with dilated cardiomyopathy or myocarditis and these results were compared with noninvasive and invasive clinical findings.

RESULTS

Of the 33 subjects, 16 (48%) had normal myocardial histologic features (Group A), 14 (42%) had changes similar to the histologic features seen with idiopathic dilated cardiomyopathy (Group B) and 3 (9%) had lymphocytic myocarditis (Group C). Presenting clinical symptoms, surface electrocardiograms (ECGs), exercise stress testing and electrophysiologic stimulation tests failed to predict the biopsy results. Twenty-four-hour ambulatory ECGs showed a statistical difference between sustained and nonsustained ventricular tachycardia in Group A versus Group B (p less than 0.007), with Group A having more sustained ventricular tachycardia. Left ventricular function measured by fractional shortening on echocardiography did not differ between groups, but left ventricular end-diastolic dimension was greater in the subjects with abnormal histologic findings (Group B) (p less than 0.03).

CONCLUSIONS

These results provide evidence that approximately 50% of children with abnormal ventricular ectopic rhythm but a structurally normal heart may have subclinical cardiomyopathy or unsuspected myocarditis.

Pulmonary hypertension and human immunodeficiency virus infection. Two reports and a review of the literature

Pulmonary hypertension may be primary (idiopathic) or secondary. While the etiologies for secondary pulmonary hypertension are diverse, infection with the human immunodeficiency virus (HIV) has not been included. To date there have been 16 reported cases of pulmonary hypertension in the HIV-infected population. Plexogenic arteriopathy was the most common pathologic finding. We report two HIV-infected patients who were concomitantly found to have pulmonary hypertension with plexogenic arteriopathy. One patient had lymphocytic interstitial pneumonitis, an entity not previously associated with pulmonary hypertension. We review the 16 previous cases of pulmonary hypertension and HIV infection and discuss this association.

Pulmonary reactions from illicit substance abuse

The epidemic spread of illicit substance abuse in the United States and the adaptation of novel modes of drug delivery have increased the incidence of pulmonary complications of drug addiction. Chest manifestations of drug abuse relate not only to the particular substance used, but also to the route of administration, the presence of contaminating foreign material or microbiologic pathogens host response, and the practice of sharing drug paraphernalia. This article outlines the important lung disorders linked to drug addiction and discusses pathophysiologic mechanisms, diagnosis, and management.

Adoptive transfer of tsk skin fibrosis to +/+ recipients by tsk bone marrow and spleen cells

The tight skin mouse (Tsk/+) is an autosomal dominant example of inherited fibrosis whose pathogenesis is unclear. Autoimmune phenomena have been described previously. This study demonstrates the adoptive transfer of skin fibrosis to lethally irradiated syngeneic +/+ recipients by the transplantation of both bone marrow and spleen cells. The recipient skin fibrosis was not associated with mast cell proliferation or degranulation as it is in the tsk/+ mouse, representing for the first time a dissociation between mast cells and fibrosis and introducing the potential for direct T cell-fibroblast interactions.

Pleural effusions associated with ethchlorvynol lung injury result from visceral pleural leak

Traditional thinking suggests that pleural fluid develops on the basis of systemic venous hypertension or a primary pleural process. Recent investigations, however, indicate that both acute lung injury and pulmonary venous hypertension can be important in the pathogenesis of pleural effusions. To evaluate the role of acute lung injury in the formation of pleural effusions, we developed a model of acute, reversible lung injury in NZW rabbits. Intravenous ethchlorvynol (ECV), known to produce permeability edema in humans, was used to produce permeability pulmonary edema in rabbits. The injury was examined over 14 days with bronchoalveolar lavage, pleural fluid analysis, and morphologic analysis. Ethchlorvynol injection (40 mg/kg) produced a PMN-predominant, exudative alveolitis (2 h), alveolar hemorrhage (6 to 10 h), and pleural effusions by 2 h (peak, 10 h). Pathologic findings included a patchy, subpleural, hemorrhagic PMN inflammatory response, which peaked by 24 h, and an acute PMN vasculitis of small arterioles and capillaries; these changes resolved in 5 to 7 days. No parietal pleural abnormalities were observed. We conclude that ECV induces an acute, reversible parenchymal lung injury resulting in a capillary leak and that fluid moves from the interstitium of the lung into the pleural space along a pressure gradient through a relatively permeable mesothelium. The data support the concept that diffuse or localized lung injury can result in pleural effusions.

A fasciocutaneous transposition flap for coverage of defects of the lower extremity

During a three-year period, eleven fasciocutaneous transposition flaps were used in ten patients to cover a defect in the lower extremity that was due to trauma or infection. The patients were subsequently evaluated with respect to survival of the flap, sensation in the flap, healing of the donor site, and postoperative morbidity. Two cases are presented for illustration. Coverage with a fasciocutaneous transposition flap proved to be safe and simple. This technique offers several advantages compared with reconstruction using microvascular free muscle transfer, and it may be preferable for many patients who have a defect distal to the knee.

Pathology of pleural infections

The pleura is protected by several tissue boundaries of differing degrees of strength. Penetration of the pleural space by mediastinal infection occurs more easily than from the lung, which in turn occurs more easily than through the diaphragm or chest wall. Infectious organisms of all classes, including bacteria, viruses, fungi, and protozoa are capable of causing pleural infection. The basic tissue response in the pleura is similar to that seen in other tissues but is modified by the peculiar anatomy of the pleura, flat serosal surfaces in constant motion against each other. Most pleural infections are initiated in the lung. Some of the most spectacular pathologic lesions are caused by aspergillus where vasculoinvasive fungi cause infected infarcts that result in round visceral pleural lesions. These in turn result in "kissing lesions" of the parietal diaphragmatic surfaces which are of the same size and shape as the visceral pleural lesions, indicating attachment and splinting of the pleural surfaces in these loci. Studies in rabbit demonstrate rapid resolution of experimental empyema with a standardized series of pathologic responses. In uncomplicated empyema, the end result is an extremely thin, almost undetectable scar. Thick fibrotic pleural lesions suggest a complicated course with continuing infection.

Inhibition of fibrosis in TSK mice by blocking mast cell degranulation

The Tsk mouse has a genetically transmitted connective tissue disease whose skin lesions resemble those of scleroderma. After treatment with disodium cromoglycate, a marked decrease in skin fibrosis was observed, raising the possibility that disodium cromoglycate may be a potential treatment for human scleroderma.

Vascular steal: the pathogenetic mechanism producing sirenomelia and associated defects of the viscera and soft tissues

Dissection of the abdominal vasculature in 11 cases of sirenomelia has demonstrated a pattern of vascular abnormalities that explains the defects usually found in this condition. The common feature is the presence of a single large artery, arising from high in the abdominal cavity, which assumes the function of the umbilical arteries and diverts nutrients from the caudal end of the embryo distal to the level of its origin. The steal vessel derives from the vitelline artery complex, an early embryonic vascular network that supplies the yolk sac. Arteries below the level of this steal vessel are underdeveloped and tissues dependent upon them for nutrient supply fail to develop, are malformed, or arrest in some incomplete stage. In contrast to the prevailing view that sirenomelia arises by posterior fusion of the two developing lower limbs, these studies suggest that the single lower extremity in sirenomelia arises from failure of the lower limb bud field to be cleaved into two lateral masses by an intervening allantois.

Thoracic surgical implications of the yellow nail syndrome

Idiopathic lymphedema associated with yellow discoloration of the nail beds constitutes the yellow nail syndrome. Pleural effusions and chronic sinusitis are also frequently present. This report describes a case of yellow nail syndrome in a 65-year-old woman.

Nodular pulmonary amyloidosis with extrapulmonary involvement

Although approximately 50 cases of nodular pulmonary amyloidosis have been described in the literature, few of them have involved bilateral confluent disease. An exceptional case with disease extensive enough to cause death by respiratory insufficiency is reported. A remarkable degree of calcification in the subpleural areas, with osseous and chondroid metaplasia, characterized the amyloid deposits. Amyloid was confined to the respiratory tract except for contiguous areas (vertebral body cortex, epicardial fat, and hilar lymph nodes). A review and update of the literature since 1974 is included.

Cellular arteriolar nodules. Their presence in heart, pancreas, and kidneys of patients with malignant nephrosclerosis

Angioblastic-appearing nodules of small arteries of heart, pancreas, and kidneys were found during microscopic study of autopsy specimens form subjects with hypertension that had responded poorly to treatment. These vascular lesions were noted in three of 15 subjects studied; they were associated with a proliferative arteriolosclerosis that was most severe in the kidney and the pancreas, but was occasionally found in the arterioles of the heart. Two of these three subjects had received treatment with dialysis; one had not. The nodules originated concentrically along a segment of small artery and consisted of a mass of mesenchymal cells and capillary-sized blood channels. There were fragmentation and focal loss of the internal elastic lamina at their points of origin, and vessel-wall necrosis in an occasional lesion. Many of these nodules appeared identical to plexiform lesions of the lung and to cellular types of Charcot-Bouchard aneurysms of the CNS.

Mycobacterium fortuitum pulmonary infection associated with an antigen-selective defect in cellular immunity

In this study we describe the first example of a well documented case of pulmonary infection caused by Mycobacterium fortuitum shown to be associated with an antigen-selective defect in cell-mediated immunity to this organism. Immunologic parameters were evaluated before, during and after antibiotic treatment with amikacin. A defect in cellular immunity to purified protein derivative from Myco. fortuitum, shown to be antigen-selective as indicated by normal responsiveness to purified protein derivative from Mycobacterium tuberculosis and several other common recall antigens, accompanied the prolonged infection by this organism. During the first three months of treatment with amikacin, the patient's clinical status improved coincident with the eradication of the organism from the sputum. During the next three months of therapy with amikacin, however, a generalized defect in cellular immunity developed, and the lung disease again progressed. The deteriorating clinical condition was presumably related to a generalized cellular immune anergy or hyporesponsiveness induced by the amikacin therapy. After three more months of treatment, the organism became resistant to the drug and reappeared in sputum cultures. Since amikacin therapy was discontinued, the patient's general immune responsiveness returned to normal. He did, however, remain unresponsive to purified protein derivative from Mycobacterium fortuitum.

Pulmonary sequelae of acute Legionnaires' disease pneumonia

Patients with acute Legionnaires' disease (LD) pneumonia may have persistent chronic pulmonary changes, as shown by the histologic appearance of specimens of lung from patients who had survived and autopsy specimens from patients who died after a protracted clinical course. Acute pneumonia was not seen in these lungs, and LD organisms could not be identified by the direct fluorescent antibody technique or the Dieterle silver impregnation strain; instead, there was organizing pneumonia with various degrees of interstitial inflammation and fibrosis. The LD pneumonia may fail to resolve, and the lung parenchyma in areas of previous acute inflammation is not restored to normal in some patients.

Histamine release from platelets for assay of byssinogenic substances in cotton mill dust and related materials

Previous reports suggest that byssinosis, an asthma-like condition among textile workers, may be mediated in part by histamine liberated following inhalation of dust. A simple, sensitive, and reliable procedure using pig platelets which contain the unusually high concentration of 0.8-1.6 microgram histamine/10(9) cells has been devised for the assay of histamine-releasing factors in cotton mill dust and related materials, and has yielded results generally in accordance with earlier assays using chopped lung tissue. As little as 50--100 microgram of total extractable substances from cotton mill dust can be measured. The activity of the extract is associated with the non-dialysable high molecular weight portion. However, conditions of acid hydrolysis do not destroy the activity. Extracts of leaves from different varieties of plant are highly potent, which suggests that the factors responsible for byssinosis are widely distributed plant components, present in textile fibre plants and converted to a respirable form by handling processes. Ellagic acid and sodium metasilicate release histamine from pig platelets, and represent new classes of compounds with possible roles in the aetiology of byssinosis.

The mineral dust load of human lungs

Studies of the dust content of lungs from non-industrially exposed city dwellers have shown that many people build up during life a total dust load of 2 grammes or more. This dust load may include up to 17 X 10(6) mineral fibres large enough to be visible with the light microscope and 360 X 10(8) fibres visible only by electron-microscopy. All lungs examined contained a small percentage of fibres that appeared structurally similar to chrysotile asbestos. It was found that the total dust content and content of light microscope sized mineral fibres was much lower in a non-industrialised city than in one with a high level of heavy industry, but levels of electron-microscope sized fibres did not differ markedly between the two groups. It would appear that these very small fibres are part of a general mineralogical background rather than resulting from industrial atmospheric pollution. This was further indicated by the fact that many of the dust particles, including large numbers of the fibrous ones proved to be derived from diatom skeletons.