Pulmonary vascular disease and hypertension after valve surgery for mitral stenosis

The reduction of pulmonary hypertension that occurs within 24 hours of valve replacement for mitral stenosis is well documented, but patients who die after surgery have not been adequately studied. Clinical and autopsy data for 16 patients who died following mitral valve replacement were reviewed. The emphasis was on preoperative and postoperative pulmonary arterial pressure and pulmonary vascular disease, including arterial, venous, and capillary changes. Morphologic features were graded and summed to obtain an additive histologic assessment (AHA). Patients were divided into three groups: 1) those who had uneventful operations and early postoperative periods but died prior to discharge; 2) those who had postoperative difficulty, with identifiable acute anatomic causes of death; and 3) those who had postoperative difficulty, with no apparent acute anatomic cause of death. In group 1 (n = 4) the preoperative pulmonary arterial pressure was 43 +/- 17 mm Hg, and AHA ranged from 0 to 4; in group 2 (n = 5) the preoperative pulmonary arterial pressure was 60 +/- 15 mm Hg, but AHA ranged only from 2 to 5. In group 3 (n = 7) the preoperative pulmonary arterial pressure was 59 +/- 12 mm Hg; AHA ranged from 6 to 9, significantly higher than that of the other groups (P less than 0.005). Three patients from group 3 had elevated pulmonary arterial pressure (60, 52, and 50 mm Hg three, six, and 15 days after surgery, respectively). Two additional patients had right heart failure with normally contracting left ventricles terminally. It is concluded that some patients with mitral stenosis who die after surgery with persistently elevated pulmonary arterial pressure have sufficiently severe pulmonary vascular disease to account for their persistent pulmonary hypertension and death.

Monoclonal antibody to an alveolar macrophage surface antigen in hamsters

A conventionally produced antibody specific for hamster lung macrophages was prepared by immunizing guinea pigs with lung macrophages from LSH (inbred) hamsters. Specificity was achieved by absorbing the resulting serum with hamster blood cells and peritoneal macrophages. This antibody was used to precipitate antigen from detergent lysates of hamster lung macrophages. To produce monoclonal antibodies, F1 hybrids of Balb C X C57Bl6 mice were immunized with these immunoprecipitates. Fusion of splenic lymphocytes from these mice with NS-1 myeloma cells produced 4 hybrid cell lines. Subcloning yielded 18 lines producing antibody reacting only with lung macrophages, and 2 lines secreting nonreactive antibody. Screening used lung and peritoneal macrophages and an ELISA assay. Using gel electrophoresis and lysates of 125I-labeled lung macrophages, all 18 lines reacted with the same antigen, a protein of 102,000 daltons. Subclasses of these monoclonal antibodies included IgG2b kappa and IgG1 kappa. Quantitative ELISA assays showed that the antibody reacted with lung macrophages of LSH and LVG (outbred) hamsters, but not with hamster resident peritoneal macrophages, spleen cells, or bone marrow cells. The antibody did not cross-react with lung or resident peritoneal macrophages from mice, rats, or guinea pigs. By flow cytometry, no reaction was detected with resident, thioglycollate-elicited, or BCG-stimulated peritoneal macrophages. When frozen sections of lung and other organs were examined by indirect immunofluorescence and immunoperoxidase methods, only alveolar macrophages were stained.

Correlation of lung macrophage age and surface antigen in the hamster

A monoclonal antibody specific for a surface antigen found on hamster lung macrophages has been produced. Macrophages obtained from LSH Syrian golden hamsters by pulmonary lavage have varying amounts of this antigen on their surface. We compared the age of alveolar macrophages (using 3H-thymidine) with the amount of surface antigen. Lung macrophages were obtained by repeated saline lavage at 1, 3, 5, and 10 days after 3H-thymidine injection. Monoclonal antibody was then reacted with these cells followed by fluorescein isothiocyanate-conjugated protein A. Cell size and fluorescence were analyzed by flow cytometry. A wide range of fluorescent intensity was observed; the cells were sorted into four subpopulations (SPs). SP1 had the lowest fluorescence per cell, and SP4 had the highest. The sorted cells were placed on glass slides, and autoradiographs were made. The percentage of labeled macrophages in each SP was determined. At 1 day after thymidine injection, cells with a paucity of antigen (SP1) were the most highly labeled; 12.5% of SP1 macrophages were labeled, but only 1.4 and 1.1% of SP3 and SP4 were labeled, respectively. The labeling was relatively even in all four SPs at 3 days, but at 5 days the labeling of cells in SP2 and SP3 was highest. By day 10, labeled macrophages had large amounts of surface antigen and were in SP3 and SP4. These findings suggest that pulmonary macrophages that have recently synthesized DNA lack surface antigen. As time passes, cells mature and more antigen is acquired. The amount of surface antigen reflects cell age and provides a useful tool to isolate and study macrophage SPs.

Differences in effects of immediate and delayed hyperoxia exposure on bleomycin-induced pulmonary injury

Several reports have suggested that patients treated with bleomycin may be at greater risk of developing respiratory failure when exposed to elevated concentrations of oxygen. We studied the interactions of bleomycin and hyperoxia in Syrian golden hamsters. Animals were instilled intratracheally with bleomycin at a dose of 0.5 unit/100 g of body weight, followed immediately by exposure to 70% oxygen for 72 hours. Mortality was 90% in these hamsters, compared to 15% in an age-matched control group treated with bleomycin alone. Postmortem studies revealed that pathologic changes were confined to the lungs which showed severe, hemorrhagic, diffuse alveolar damage. To determine the effect of delaying exposure to hyperoxia, bleomycin at a dose of 0.5 unit/100 g of body weight was instilled and animals were kept in room air for 1 and 2 months before exposure to 70% or 100% oxygen for 72 hours. No significant increase in mortality or interstitial pneumonitis and fibrosis was seen in these groups during or after the hyperoxic exposures. Mortality in controls treated with saline and hyperoxia was zero. We conclude that simultaneous treatment with bleomycin and hyperoxia results in a synergistic effect on mortality and on the development of pulmonary fibrosis. However, there is no synergism if the hyperoxic exposure is delayed for at least 1 month following bleomycin treatment.

Effects of inhaled ammonium sulfate on benzo[a]pyrene carcinogenesis

The effect of inhaled ammonium sulfate on benzo[a]pyrene carcinogenesis in the lungs of Syrian golden hamsters was studied. Exposure to ammonium sulfate at an airborne concentration 20 times average United States ambient levels resulted in a significant depression (p less than 0.05) of benzo[a]pyrene carcinogenesis in the first 6 mo of the study. However, at 2 yr, the termination of the study, there were no differences in cancer incidence between groups receiving benzo[a]pyrene and benzo[a]pyrene plus ammonium sulfate. In addition, at the concentration studied, inhaled ammonium sulfate did not significantly increase the incidence or severity of pneumonitis or pulmonary fibrosis in the hamster. However, this inhalation did increase the incidence of emphysema but not the severity. The decreased incidence of cancer during the first 6 mo of this study in animals receiving both benzo[a]pyrene and ammonium sulfate suggests that interaction between sulfate and benzo[a]pyrene does occur, but is insufficient to afford long-term protection against the development of cancer. No enhancement of carcinogenesis by benzo[a]pyrene occurs in the presence of inhaled sulfate.

Alterations in alveolar macrophages in hamsters developing pulmonary fibrosis

Hamsters treated with intratracheally instilled bleomycin (0.16 U/100 g) followed by a 72-hr exposure to 70% oxygen develop a slowly progressive interstitial pneumonitis with fibrosis. Lung lavage was performed during fibrogenesis at 30, 60, and 120 days after treatment. The number of macrophages recovered was increased at all of these times. Macrophages were evaluated using flow cytometry and a monoclonal antibody specific for a surface antigen present on mature lung macrophages but deficient in younger cells. The mean density of antigenic sites per cell surface area was significantly lower than control values at the three times studied (-24.7, -20.0, and -20.9%). Thus, a significant fraction of macrophages present in this model of progressive pulmonary fibrosis are immature. The in vivo uptake of radioactive colloidal gold by the pulmonary macrophages was also determined. Thirty days after treatment, macrophage endocytosis of colloidal gold was reduced by 22% of control. The total number of harvested macrophages increased twofold, however, a change that usually increases endocytotic rates. It is concluded that macrophages are increased during fibrogenesis and that this increase is caused by a continued influx of new macrophages. In addition, the phagocytic function of these macrophages is less efficient.

Progressive pulmonary fibrosis in hamsters

The concomitant treatment of hamsters with bleomycin and hyperoxia results in a synergistic development of pulmonary injury. We exposed hamsters for 72 hr to 70% oxygen following a single intratracheal instillation of bleomycin (0.16 U/100 g body weight). Groups of 10 animals were killed at 3, 6, 10, 30, 60, 90, and 120 days after instillation for histopathologic and morphometric assessment. Diffuse alveolar damage developed acutely. At 30 days, the intense acute cellular infiltrate had subsided, leaving a focal interstitial pneumonitis. Morphometric quantitation at 10 days revealed that 33.5 +/- 5.3% (x +/- SE) of the lung was diseased; there was apparent healing by 30 days, when 10.5 +/- 2.0% of the lung was diseased. However, progression to diffuse pneumonitis with fibrosis was seen at 60, 90, and 120 days, when 30.2 +/- 4.9%, 38.5 +/- 5.8%, and 38.8 +/- 4.5% of the lung was diseased, respectively. In vivo pulmonary function studies on treated animals at 25 and 55 days showed decreasing dynamic compliance and increased minute ventilation, which corroborates the presence of interstitial fibrosis. We conclude that simultaneous treatment of hamsters with bleomycin and hyperoxia results in interstitial fibrosis with a distribution and progression that mimics human pulmonary fibrosis. This model appears ideally suited for the study of progressive fibrosis and will be useful when development of a widely distributed lesion is crucial.

Malignant mesothelioma in urban dogs

Clinical and postmortem materials from six dogs with a diagnosis of malignant mesothelioma were studied retrospectively. The dogs were urban pets with clinical signs of malignant effusions. Two mesotheliomas were pleural, one pericardial, and one peritoneal. Both pleura and pericardium were involved in one dog, and the pleura and peritoneum in another. On gross examination at necropsy, diffuse granular or velvety plaques covering mesothelial surfaces were found in all dogs; firm discrete pleural nodules also were present in two dogs. Neither distant metastases nor areas of deep lung invasion were found. The tumors varied histologically, but the most common type was epithelial with a papillary pattern. Ultrastructurally, the neoplastic cells had prominent surface microvilli, numerous desmosomes, and tonofilaments. Lung tissue from these dogs and from control dogs was evaluated for the presence of ferruginous bodies. Asbestos bodies were found in three of five dogs with mesotheliomas but rarely were found in control dogs. As a group, the mesothelioma cases had significantly more asbestos bodies and total ferruginous bodies than controls. The clinical and morphologic appearance of canine mesothelioma is similar to human mesothelioma and also may be associated with exposure to airborne fibers.

Retention of inhaled particles in hamsters with pulmonary fibrosis

Aerosol retention was studied in hamsters 30, 60, and 90 days after the initiation of interstitial pulmonary fibrosis by a combination of bleomycin (bleo), 0.16 U/100 g body weight given intratracheally, and O2, for 72 h. Groups of bleo-O2-treated and control animals were exposed (awake) for 25 min to a 99mTc-labeled insoluble aerosol (activity median aerodynamic diameter, 0.45 micron; geometric standard deviation, 1.3). Within 5 min after exposure, the hamsters were killed and their lungs were excised and dried at total lung capacity, and sliced into 1-mm sections. Slices were dissected into pieces, and an evenness index (EI) was calculated for each piece (formula: see text). With uniformity of retention, all Els would be 1. The distribution of Els in control animals had a mean of 1.0 and a SD of 0.27; 0% of the Els were less than or equal to 0.20. Total retention diminished and was less uniform in bleo-O2-treated animals. At 30 days, the SD increased to 0.62, and 6% of the Els were less than or equal to 0.20. At 60 and 90 days, nonuniformity decreased but was still greater than that in the control animals (SD60 = 0.42, SD90 = 0.36). When examined histologically, individual pieces with low Els had more disease than those with high Els. Local decreases in compliance caused by fibrosis may have altered regional ventilation and retention. Our data also correlate with the progression of fibrosis from a focal lesion at 30 days to a more diffuse lesion at 90 days.

Imaging of lymphoid structures with indium-111-labeled lymphocytes

The ability of indium-111 (111In)-oxine-labeled syngeneic lymphocytes to migrate normally and their suitability for imaging both normal lymphoid structures and those with metastatic disease were assessed. Sixty-two ACI rats were studied, 34 of which received injections in the left foot pad with 1 X 10(6) syngeneic H-4-II-E hepatoma cells nine to 44 days before imaging. Most animals were bearing palpable tumors when imaged. In 53 experiments, 1-6 X 10(8) 111In-oxine-labeled lymphocytes with a labeling concentration of 5-80 microCi/10(8) cells were injected intravenously. Gamma camera images were obtained 22 hours later. After the last image, the animals were killed. The lymph nodes, liver, spleen, lungs, and left femur were dissected, and the recovered radioactivity was determined in a gamma well counter. Lymph nodes could be partially or completely visualized in 70% of the animals (15 tumor-bearing and 16 normal out of 44 technically satisfactory experiments). Large metastatic nodes were seen clearly. Lymphocytes labeled with 111In-oxine exhibited a normal migration from blood to lymph nodes.

Leukemic cell lysis pneumonopathy. A complication of treated myeloblastic leukemia

The course of acute noninfectious pulmonary infiltrates in five patients with myeloblastic leukemia was evaluated. All had circulating blast cells (range, 245-192,000/mm3) and recently had received chemotherapeutic drugs for their leukemia. Within four days of the nadir of their leukocyte counts, a patchy, often multilobar pneumonitis developed. Cultures for bacteria, fungi, and viruses were all negative, and no clinical response was observed to broad-spectrum antibiotics. On lung biopsy, pathologic changes were characterized by diffuse alveolar damage with degenerating blast cells in the interstitium and in organizing alveolar exudates. No potential pathogenic organisms were seen on light or electron microscopy of the biopsy samples. In each case the pulmonary infiltrate resolved without specific therapy. We postulate that lysis of leukemic cells, with subsequent release of their enzyme contents, led to the diffuse alveolar damage observed pathologically. Leukemic cell lysis pneumonopathy may be one of the potential causes of pulmonary infiltrates in leukemic patients and can be distinguished pathologically by its distinctive pattern.

Potentiation of bleomycin-induced lung injury by exposure to 70% oxygen. Morphologic assessment

The effects of a single intratracheal instillation of bleomycin followed by exposure to 70% oxygen for 72 h were studied in hamsters. Mortality increased markedly among hamsters exposed to 70% oxygen for 72 h after bleomycin instillation, compared with animals receiving bleomycin and breathing room air. The lethal dose required to kill 50% of the hamsters at 30 days (LD50, 30 day) for bleomycin alone was 0.73 U/100 g body weight, whereas the LD50, 30 day for bleomycin followed by 70% oxygen fell to 0.23 U/100 g body weight. Using morphometry and light microscopy, we found that the amount of diseased lung increased in hamsters given bleomycin with hyperoxia compared with that in those treated with bleomycin alone. After 0.20 U bleomycin and air, 2.8 +/- 1.6% of the lung was abnormal, but with 0.20 U bleomycin followed by 70% oxygen, 42.7 +/- 17.9% of the lung was abnormal. At bleomycin doses that produced no apparent lesions, the addition of 70% oxygen for 72 h produced focal interstitial fibrosis at 30 days. Neither mortality nor significant histologic changes were seen in hamsters treated with saline followed by exposure to 70% oxygen for 72 h. This study demonstrates that hyperoxia potentiates bleomycin damage and suggests that the use of elevated oxygen concentrations in patients being treated with bleomycin should be minimized.

Factors associated with correct antemortem diagnosis of major pulmonary embolism

Difficulties persist in the accurate clinical diagnosis of major pulmonary embolism despite the availability of lung scans and pulmonary angiography. To evaluate factors associated with the correct antemortem diagnosis of pulmonary embolism, we reviewed all 1,455 autopsy reports at the Peter Bent Brigham Hospital from 1973 to 1977. Of 54 patients identified with anatomically major pulmonary embolism at autopsy, 16 (30 percent) had correct antemortem diagnosis. Accuracy was far greater in postoperative patients (64 percent) (p = 0.02) and in patients with autopsy-proved venous thrombosis (55 percent) (p = 0.005). Lung scanning (82 percent) (p = 0.0002) and pulmonary angiography (80 percent) (p = 0.05) during the 10 days prior to death were also associated with an increased tendency to correct clinical diagnosis of pulmonary embolism. In contrast, among 21 patients with autopsy-proved major pulmonary embolism who also had pneumonia, no pulmonary embolism was diagnosed before death (p = 0.0001). Furthermore, among patients 70 years of age or older, only 10 percent with pulmonary embolism at postmortem examination had a correct diagnosis prior to death (p = 0.02). In patients with pneumonia or in elderly patients, an increased awareness of the possibility of pulmonary embolism and more frequent use of lung scanning and pulmonary angiography may increase the accurate clinical diagnosis of pulmonary embolism.

Pathologic patterns of Serratia marcescens pneumonia

To characterize the pulmonary lesions caused by Serratia marcescens, the authors reviewed all autopsy-culture-proven cases of S. marcescens pneumonia occurring at their hospital between 1968 and mid-1980. In 16, S. marcescens was the only organism cultured from the lungs during life or at autopsy. This report describes primarily these pure infections. Two histopathologic reactions were seen. Nine non-neutropenic patients had acute, hemorrhagic bronchopneumonia, seven with microabscesses and two with larger cavities. In seven, distinctive vasculitis was apparent in vessels larger than 75 microns in diameter; intramural gram-negative rods were identified in two. Seven immunosuppressed patients had diffuse neutropenic pneumonitis resembling diffuse alveolar damage, with extensive intra-alveolar fibrinous exudates and pulmonary hemorrhage. In two patients, bacteria without cellular reaction were present. In patients with prolonged infections, focal areas of intra-alveolar organization and bronchiolitis obliterans accompanied both patterns. Since the incidence of nosocomial S. marcescens infection is increasing and since pneumonia caused by this organism is recognizable histologically, autopsy cultures positive for S. marcescens should not be disregarded.

Peritoneal responses to implanted fabrics used in operating rooms

Fibers obtained from woven and nonwoven surgical fabrics were operatively instilled into the peritoneal cavities of rats to assess pathologic responses at 2, 8, 16, and 32 weeks postoperatively. Adhesions were found in 20% of the sham-operated animals and in 22% and 29% of the animals with fibers from woven and nonwoven fabrics, respectively. These differences were not significant. The adhesions were not progressive with time and were not related to increased morbidity or mortality rates. Foreign-body granulomas were found in 8% of the sham-operated animals and in 96% and 89% of the animals with fibers from woven and nonwoven fabrics, respectively. Differences between the groups with fibers were not significant. There were no morphologic differences in the granulomas of woven and nonwoven materials; they did not increase in number of enlarge with time. We conclude that responses to cellulose fibers, whether from cotton or from nonwoven materials produced from wood fibers, are virtually identical.

Sex-related differences in tumor progression associated with altered lymphocyte circulation

Male and female ACI rats were inoculated with the syngeneic H-4-II-E hepatoma, and the natural history of the tumor, histopathology, and lymphocyte migration were studied. The tumor formed a.s.c. mass in all 16 males and in 22 of the 26 females given injections. In the males, tumors progressed, and all animals died with the mean survival time of 54 days. Complete tumor regression was observed in all but two females. In the females, there was prominent lymphocytic infiltration of the tumor, while males had no cellular reaction at the tumor site. The regional lymph nodes in males usually contained metastases and were nonreactive. The female lymph nodes did not contain metastases but contained many lymphocytes within the peripheral sinus and sinusoids. Six male-female pairs were castrated before tumor inoculation. Castration had no effect on the natural history or the etiology of the tumor. Comparing seven normal control male-female littermate pairs, there were no differences in lymphocyte accumulation in the lymph nodes 22 hr following injection of 51Cr-labeled syngeneic lymphocytes. In seven tumor-bearing male-female littermate pairs, there was a significant decrease in lymphocyte migration to the lymph nodes (p less than 0.001) in tumor-bearing males as compared to that in both their female littermates and control males. Depressed lymphocyte circulation in the males was associated with rapid progression of tumors resulting in the death of the animals. Unimpaired lymphocyte mobilization in the tumor-bearing females was associated with complete regression in most animals.

Serratia pneumonia

The clinical and radiological manifestations were correlated with the necropsy findings in the lungs of 18 patients who died of Serratia marcescens infection. Ten died during a hospital epidemic affecting 74 patients. In 14, only Serratia was identified at autopsy; in 4, other organisms were also cultured. Ten patients had septicemia. The predominant radiological findings were focal bronchopneumonia in 13, lobar consolidation in 2, and diffuse nonhomogeneous infiltrates in 10. Small radiolucent areas within the infiltrates were seen in 5, a large pulmonary abscess in 1, and pleural effusion in 7. The predominant pathological findings were focal necrotizing bronchopneumonia (sometimes with microscopic abscesses) in 14 and diffuse hemorrhage in 3. Three patients had endocarditis and 3 others showed dissemination to the brain or kidneys.

An automated method for the determination of sulfate

An automated method of sulfate analysis is described, which can detect sulfate concentrations as low as 2.5 mug per ml water. The assay is based on the reaction of sodium rhodizonate and barium forming a colored complex. Sulfate quantitavely interferes with this reaction. The assay is reproducible in the range of 2.5 to 30 mug sulfate per ml water. This method conveniently and accurately measures water soluble sulfate filtered from the air, and is especially useful in assaying samples containing microgram quantities of sulfate from experimental inhalation apparatus.

The origin of alveolar macrophages in mouse radiation chimeras

This investigation attempted to determine whether the primary source of alveolar macrophages is pulmonary or hematopoietic. We have utilized an antigenic marker to identify cells of hematopoietic origin. Mouse chimeras were produced by irradiating C57B6/AF(1) mice (900 R) and then injecting them intravenously with B10D2/AF(1) bone marrow. The donor animal has an antigenic specificity on the H-2 locus, not shared by the recipient. Alveolar macrophages were obtained by repeated lung washings with physiologic saline at 37 degrees C. Cytotoxic tests were done on bone marrow and alveolar macrophages using anti-31 mouse antibody, absorbed rabbit serum as complement, and trypan blue exclusion as a test for viability. Animals were studied at 7, 14, 21, 28, and 35-50 days and 4, 5, 8, and 11 months after irradiation and bone marrow replacement. By 21 days after irradiation, 90% of the animals had greater than 80% replacement of marrow with donor tissue; and white blood cell and alveolar macrophage counts approached normal. At this time and at later intervals the per cent of donor cells in the lung free cell population was not significantly different from the per cent of donor cells in the bone marrow. Similarly, after aerosol particulate exposure, the percentage of marrow cells and alveolar macrophages of donor origin were not significantly different. This immunologic approach suggests that alveolar macrophages in radiation chimeras are entirely of hematopoietic origin.