Tomographic fluorescence imaging in tissue phantoms: a novel reconstruction algorithm and imaging geometry.

A novel image reconstruction algorithm has been developed and demonstrated for fluorescence-enhanced frequency-domain photon migration (FDPM) tomography from measurements of area illumination with modulated excitation light and area collection of emitted fluorescence light using a gain modulated image-intensified charge-coupled device (ICCD) camera. The image reconstruction problem was formulated as a nonlinear least-squares-type simple bounds constrained optimization problem based upon the penalty/modified barrier function (PMBF) method and the coupled diffusion equations. The simple bounds constraints are included in the objective function of the PMBF method and the gradient-based truncated Newton method with trust region is used to minimize the function for the large-scale problem (39919 unknowns, 2973 measurements). Three-dimensional (3-D) images of fluorescence absorption coefficients were reconstructed using the algorithm from experimental reflectance measurements under conditions of perfect and imperfect distribution of fluorophore within a single target. To our knowledge, this is the first time that targets have been reconstructed in three-dimensions from reflectance measurements with a clinically relevant phantom.

The hypereosinophilic syndrome presenting with eosinophilic mastitis.

A case of the hypereosinophilic syndrome presenting with eosinophilic mastitis is described. The histopathology of the mastitis is illustrated and the patient's clinical course reported.

Effect of transdermal nicotine delivery as an adjunct to low-intervention smoking cessation therapy. A randomized, placebo-controlled, double-blind study.

To assess the smoking cessation efficacy of transdermal nicotine patches as an adjunct to low-intervention therapy, we conducted a double-blind, placebo-controlled trial in 158 smokers. Participants were randomly assigned to one of the following three study regimens that required daily application of two 15-cm2 patches: (1) 24-hour nicotine delivery, (2) nicotine delivery during wakeful hours only, and (3) placebo. The impact of the three regimens on smoking cessation rates and tobacco withdrawal symptoms was examined. During the last 2 weeks of the trial, 39% of the 24-hour nicotine regimen delivery group, 35% of those on wakeful hour nicotine regimens, and 13.5% of the placebo treatment group achieved abstinence. Self-reported quit rates for the two nicotine patch-wearing regimens, as compared with that for the placebo group, continued to be significantly higher at 6 months. Moreover, compared with placebo, the transdermal nicotine patches significantly reduced tobacco withdrawal symptoms during the first few weeks of quitting. The differences in quit rates and tobacco withdrawal symptoms between the two active groups were not statistically significant. The patches were well tolerated both topically and systemically. We concluded that transdermal nicotine, when used as an adjunct to low-intervention therapy, significantly reduced tobacco withdrawal symptoms and enhanced smoking cessation rates.

Quantitative culture of bronchoalveolar lavage fluid for the diagnosis of bacterial pneumonia.

PURPOSE: A prospective study to determine the usefulness of quantitative bacterial cultures of fluid obtained via fiberoptic bronchoscopy and bronchoalveolar lavage as an aid in the diagnosis of bacterial pneumonia. PATIENTS AND METHODS: All patients undergoing fiberoptic bronchoscopy with bronchoalveolar lavage during a 6 1/2-month period. Presence of pneumonia was determined using clinical, radiographic, laboratory, and histologic data. Quantitative bacterial cultures of bronchoalveolar lavage fluid were determined using a 1-microL culture loop. RESULTS: Quantitative bacterial cultures of bronchoalveolar lavage (BAL) fluid were sensitive and specific predictors of bacterial pneumonia. Using 10(3) colony-forming units (cfu)/mL as the threshold value for a positive culture, we determined the sensitivity and specificity to be 90% and 97%, respectively. The data were also analyzed for the subgroups of patients who were intubated or were receiving antibiotics. The sensitivity and specificity were 78% and 96% for the group of patients receiving antibiotics and 100% and 82% for the group of patients intubated for more than 24 hours at the time of BAL. Values for the area under the receiver operating characteristic curve for the 3 groups were 0.94, 0.88, and 0.96, respectively. CONCLUSIONS: Quantitative bacterial cultures of BAL fluid are sensitive and specific in the diagnosis of bacterial pneumonia. The use of antibiotics at the time of BAL reduces the sensitivity of the test, and prolonged intubation reduces the specificity of the test.

Diffuse alveolar hemorrhage in autologous bone marrow transplant recipients.

PURPOSE: The purpose of our work was to evaluate pulmonary complications in autologous bone marrow transplant recipients. PATIENTS AND METHODS: A total of 141 consecutive autologous bone marrow transplant recipients were evaluated. In 29 patients, a clinical syndrome characterized by progressive dyspnea, hypoxia, cough, diffuse consolidation on chest roentgenography, and characteristic bronchoalveolar lavage findings developed over one to seven days. RESULTS: In 29 patients, bronchoalveolar lavage performed by sequential instillation and aspiration of 20-ml aliquots of normal saline resulted in recovered lavage fluid that became progressively bloodier with each recovered aliquot. Autopsy and bronchoalveolar lavage in these patients revealed no pathogens that accounted for the clinical findings. Since the later aliquots sample predominantly alveolar material, this syndrome was termed diffuse alveolar hemorrhage (DAH). DAH was associated with a high inpatient mortality rate (23 of 29 died versus 14 of 112 without DAH, p less than 0.001) and was associated with age over 40 years, solid malignancies, high fevers, severe mucositis, white blood cell recovery, and renal insufficiency (p less than 0.05, compared with patients without DAH). However, DAH was not associated with prolonged prothrombin or partial thromboplastin times or decreased platelet counts compared with patients without DAH. CONCLUSION: DAH is a frequent cause of respiratory compromise and a major cause of mortality in autologous bone marrow transplant recipients.

Characterization of autoantibodies to vasoactive intestinal peptide in asthma.

Vasoactive intestinal peptide (VIP) is a potent relaxant of the airway smooth muscle. In this study, VIP-binding autoantibodies were observed in the plasma of 18% asthma patients and 16% healthy subjects. Immunoprecipitation studies and chromatography on DEAE-cellulose and immobilized protein G indicated that the plasma VIP-binding activity was largely due to IgG antibodies. Saturation analysis of VIP binding by the plasmas suggested the presence of one or two classes of autoantibodies, distinguished by their apparent equilibrium affinity constants (Ka). The autoantibodies from asthma patients exhibited a larger VIP-binding affinity compared to those from healthy subjects (Ka 7.8 x 10(9) M-1 and 0.13 x 10(9) M-1, respectively; P less than 0.005). The antibodies were specific for VIP, judged by their poor reaction with peptides bearing partial sequence homology with VIP (peptide histidine isoleucine, growth hormone releasing factor and secretin). IgG prepared from the plasma of an antibody-positive asthma patient inhibited the saturable binding of 125I-VIP by receptors in guinea pig lung membranes (by 39-59%; P less than 0.001). These observations are consistent with a role for the VIP autoantibodies in the airway hyperresponsiveness of asthma.

Serum angiotensin-converting enzyme is elevated in association with underground coal mining.

Serum angiotensin-converting enzyme activity (SACE) and lysozyme activity were measured in a group of 40 underground coal miners and two control groups, 20 subjects with sarcoidosis and 15 normal non-dust-exposed volunteers. The miners were grouped first according to whether they had recent exposure (still actively mining or retired three years or less prior to measurement) or temporally more distant exposure (retired more than three years prior to measurement). Secondly, they were grouped as to whether or not they had coal workers' pneumoconiosis (CWP). The subjects with sarcoidosis were grouped according to disease activity. As expected, the subjects with active sarcoidosis had elevated SACE activity compared with normal subjects. The coal miners as a group did not have elevation of their SACE activity. However, the coal miners with recent exposure had elevated SACE activity (57.1 +/- 3.9 U/ml) compared with normal controls (43.8 +/- 1.5 U/ml, p = 0.007). The SACE activity in miners without recent exposure was not elevated (39.8 +/- 1.3 U/ml) compared with the normal controls. No increase in SACE activity was found when the miners were grouped according to the presence or absence of CWP. In contrast, the miners' serum lysozyme activity was not elevated. Since alveolar macrophages are a potential source of SACE, elevation of SACE activity in underground coal miners may reflect alveolar macrophage activation caused by increased pulmonary mixed coal mine dust burden. Furthermore, since both SACE and serum lysozyme are elevated in association with silicosis, these findings may confirm that the macrophage responses to inhaled silica and coal dust differ.

Detection of cytomegalovirus in bronchoalveolar lavage specimens. Spin amplification and staining with a monoclonal antibody to the early nuclear antigen for diagnosis of cytomegalovirus pneumonia.

To diagnose cytomegalovirus pneumonia in a hetergeneous population of patients, three methods for detection of CMV in bronchoalveolar lavage specimens were compared as follow: (1) spin amplification followed by staining with a monoclonal antibody to the early nuclear antigen (EA-assay); (2) conventional tissue cell culture; and (3) cytology. Cell differentials were performed on most specimens. Cytomegalovirus was detected by one or more method in 55 BAL specimens from 39 patients. Cytomegalovirus (CMV) pneumonia was diagnosed by lung tissue (primarily autopsy) histologic findings and conventional culture results or the presence of CMV in extrapulmonary tissue, fulfillment of specific clinical and radiographic criteria plus failure to recover a pathogen other than CMV from a respiratory specimen. Probable CMV pneumonia was diagnosed if only the latter two criteria were met. The EA-assay was positive in all patients with proven or probable CMV pneumonia and in 92 percent of those without documented pneumonia. Cytologic findings were positive only in patients with CMV pneumonia but were negative in one-third of those patients. As a diagnostic test for CMV pneumonia, the EA-assay, conventional culture, and cytology had positive predictive values of 45, 57, and 100 percent, respectively. Lymphocyte percentages in BAL specimens from patients with CMV pneumonia were significantly decreased compared with those of patients without CMV pneumonia (p less than 0.005). Although the EA-assay should not be used alone as a diagnostic test for CMV pneumonia in our patient population, the combination of alveolar lymphopenia and a positive BAL CMV EA-assay was highly suggestive of disease.

Chronic inflammation is associated with an increased proportion of goblet cells recovered by bronchial lavage.

To evaluate the possibility that bronchoalveolar lavage could provide sufficient respiratory epithelial cells to quantify changes in epithelial cell types associated with chronic inflammation, we examined the epithelial cells obtained in the first infused (20 ml) aliquots that were processed separately from later aliquots, a process known to enrich for bronchial contents. Epithelial cells, including ciliated cells, goblet cells, and fragments of desquamated epithelium, were easily identified after preparation by cytocentrifugation and staining with a modified Giemsa stain. Quantification of the columnar cell types revealed that those with chronic bronchitis and asymptomatic smokers have increased goblet cells as a percentage of the total columnar epithelial cells (chronic bronchitics 36 +/- 2 percent, asymptomatic smokers 22 +/- 2 percent) compared with normal subjects (9 +/- 1 percent, p less than 0.001, ANOVA). Significantly, the goblet cell percentage was strongly correlated with other measures of bronchitis and measures of airflow obstruction such as the bronchitis index, a visually derived score at bronchoscopy of airway inflammation (r = 0.72, p less than 0.001), the percent neutrophils in the first infused aliquots (r = 0.44, p less than 0.05), and the FEV1 percent (r = -0.74, p less than 0.001). Thus, bronchoalveolar lavage is capable of providing sufficient bronchial epithelial cells for analysis, and the changes seen in the spectrum of columnar epithelial cells may reflect important underlying pathologic changes.

The bronchitis index. A semiquantitative visual scale for the assessment of airways inflammation.

Flexible fiberoptic bronchoscopy has been proven to be an effective tool for the assessment and characterization of airway inflammation. Visual inspection of airways affected by chronic bronchitis discloses an abnormal appearance characterized by erythema, edema, secretions, and friability. It was hypothesized that the visual appearance of airway inflammation could be assessed in a semiquantitative manner. A bronchitis index (BI) was developed that scores the visual appearance of airways according to the presence or absence of abnormal edema, erythema, secretions, and friability (0 = normal, 3 = remarkably abnormal). The BI was determined in three study groups: 86 subjects with chronic bronchitis, 15 subjects who smoked cigarettes, but did not have chronic bronchitis, and 25 normal, nonsmoking control subjects. The reproducibility of the BI was determined by comparing the results from pairs of two independent observers assessing 249 subjects undergoing fiberoptic bronchoscopy under various investigative protocols. In total, nine investigators scored the airways. For the three observer pairs with more than six observations, there were no differences noted in the BI (p = 0.43, 0.67, 0.82). To control for the effect of cough upon the BI, lidocaine usage was recorded. No correlation was found between lidocaine usage and BI. As previously noted for a smaller group of subjects, the BI was found to be elevated in those with chronic bronchitis (13.2 +/- 0.53) compared with both asymptomatic smokers (8.5 +/- 0.89, p < 0.0005) and normal volunteers (2.3 +/- 0.55, p < 0.0001); the latter two groups also differed significantly (p < 0.0001). The BI was also found to correlate significantly with bronchial sample lavage fluid neutrophil content in lavage fluid obtained after determination of the BI and with cigarette smoking as quantitated by pack years. Conversely, the BI correlated negatively with the spirometric measures of airway obstruction, FEV1, FEV1/FVC, FEV25-75, and FEFmax. Thus, the BI appears to be a reproducible, semiquantitative assessment of the visual appearance of airway inflammation. It may be a useful bronchoscopic adjunct for the assessment of airway inflammation in clinical investigations.

General vs local anesthesia. Effect on bronchoalveolar lavage findings.

Bronchoalveolar lavage (BAL) can be performed with the patient undergoing either local or general anesthesia (GA). This study investigates whether the type of anesthesia affects BAL fluid and cell recovery. Eighty patients, were selected for study. Fluid recoveries were significantly less in the GA group for both the bronchial and alveolar lavages. The differences were confirmed for BAL fluid recovery in a subsequent group of 120 unselected patients. Bronchoscope size did not appear to affect recovery, nor did anesthesia time; BAL fluid recovery from patients with respiratory failure who were intubated and mechanically ventilated was similar to that in the GA group, suggesting that lower recovery rates may be due to mechanical ventilation. The BAL fluid cell counts were related to fluid recovery, but airway neutrophils represented a higher percentage of BAL lavage fluid cells in the GA lavages, independent of differences in the volume of lavage fluid recovered.

Protease injury in airways disease.

In summary, proteases are present in the airway in inflammatory airways disease. These enzymes can damage the airway epithelium. As a consequence, airway function can be altered, and long-term changes in airway anatomy can result. Although the exact cellular and biochemical mechanisms that lead to these changes are incompletely described, it seems likely that they will play important roles in clinical airways disease. As such, these pathways may represent novel opportunities for therapeutic intervention.

Cystic adenomatoid malformation involving an entire lung in a 22-year-old woman.

Congenital cystic adenomatoid malformation is an uncommon cause of respiratory distress in infants and is a rare entity in adults. Presentation in older patients is that of recurrent pulmonary infections. Usually a single lobe is involved. This report describes congenital cystic adenomatoid malformation involving the entire right lung in a 22-year-old woman presenting with gastrointestinal bleeding due to cavernous transformation of the portal and splenic veins.

Diagnostic imaging of breast cancer using fluorescence-enhanced optical tomography: phantom studies.

Molecular targeting with exogenous near-infrared excitable fluorescent agents using time-dependent imaging techniques may enable diagnostic imaging of breast cancer and prognostic imaging of sentinel lymph nodes within the breast. However, prior to the administration of unproven contrast agents, phantom studies on clinically relevant volumes are essential to assess the benefits of fluorescence-enhanced optical imaging in humans. Diagnostic 3-D fluorescence-enhanced optical tomography is demonstrated using 0.5 to 1 cm(3) single and multiple targets differentiated from their surroundings by indocyanine green (micromolar) in a breast-shaped phantom (10-cm diameter). Fluorescence measurements of referenced ac intensity and phase shift were acquired in response to point illumination measurement geometry using a homodyned intensified charge-coupled device system modulated at 100 MHz. Bayesian reconstructions show artifact-free 3-D images (3857 unknowns) from 3-D boundary surface measurements (126 to 439). In a reflectance geometry appropriate for prognostic imaging of lymph node involvement, fluorescence measurements were likewise acquired from the surface of a semi-infinite phantom (8x8x8 cm(3)) in response to area illumination (12 cm(2)) by excitation light. Tomographic 3-D reconstructions (24,123 unknowns) were recovered from 2-D boundary surface measurements (3194) using the modified truncated Newton's method. These studies represent the first 3-D tomographic images from physiologically relevant geometries for breast imaging.

Assessment of airways inflammation utilizing bronchoalveolar lavage.

Pathologic correlations and examination of expectorated sputum have suggested that chronic bronchitis is an inflammatory disorder of the airways. Bronchoscopy and bronchoalveolar lavage provide a means for sampling airway epithelial lining fluid. Application of bronchoscopy and bronchoalveolar lavage to a group of patients with chronic bronchitis confirms the association of airways inflammation and chronic bronchitis.

Pathogenesis, evaluation, and therapy for massive hemoptysis.

Massive hemoptysis is a rare, but life-threatening event. Death from massive hemoptysis is usually due to aspiration of blood. Thus, the initial evaluation should occur simultaneously with efforts to control the patient's airway and respiratory status. Therapeutic interventions can be directed with an understanding of the underlying pathophysiology and estimated rate of blood loss. Surgery remains the definitive therapy. However, more conservative measures can usually control acute bleeding and provide therapeutic alternatives for patients who are not surgical candidates.

Imaging of spontaneous canine mammary tumors using fluorescent contrast agents.

We present near-infrared frequency-domain photon migration imaging for the lifetime sensitive detection and localization of exogenous fluorescent contrast agents within tissue-simulating phantoms and actual tissues. We employ intensity-modulated excitation light that is expanded and delivered to the surface of a tissue or tissue-simulating phantom. The intensity-modulated fluorescence generated from within the volume propagates to the surface and is collected using a gain-modulated image-intensified charge-coupled device camera. From the spatial values of modulation amplitude and phase of the detected fluorescent light, micromolar volumes of diethylthiatricarbocyanine iodide (tau = 1.17 ns) and indocyanine green (ICG) (tau = 0.58 ns) embedded 1.0 cm deep in a tissue phantom are localized and discriminated on the basis of their lifetime differences. To demonstrate the utility of frequency-domain fluorescent measurements for imaging disease, we image the fluorescence emitted from the surface of in vivo and ex vivo canine mammary gland tissues containing lesions with preferential uptake of ICG. Pathology confirms the ability to detect spontaneous mammary tumors and regional lymph nodes amidst normal mammary tissue and fat as deep as 1.5 cm from the tissue surface.

Pharmacokinetics of ICG and HPPH-car for the detection of normal and tumor tissue using fluorescence, near-infrared reflectance imaging: a case study.

We present in vivo fluorescent, near-infrared (NIR), reflectance images of indocyanine green (ICG) and carotene-conjugated 2-devinyl-2-(1-hexyloxyethyl) pyropheophorbide (HPPH-car) to discriminate spontaneous canine adenocarcinoma from normal mammary tissue. Following intravenous administration of 1.0 mg kg-1 ICG or 0.3 mg kg-1 HPPH-car into the canine, a 25 mW, 778 nm or 70 mW, 660 nm laser diode beam, expanded by a diverging lens to approximately 4 cm in diameter, illuminated the surface of the mammary tissue. Successfully propagating to the tissue surface, ICG or HPPH-car fluorescence generated from within the tissue was collected by an image-intensified, charge-coupled device camera fitted with an 830 or 710 nm bandpass interference filter. Upon collecting time-dependent fluorescence images at the tissue surface overlying both normal and diseased tissue volumes, and fitting these images to a pharmacokinetic model describing the uptake (wash-in) and release (wash-out) of fluorescent dye, the pharmacokinetics of fluorescent dye was spatially determined. Mapping the fluorescence intensity owing to ICG indicates that the dye acts as a blood pool or blood persistent agent, for the model parameters show no difference in the ICG uptake rates between normal and diseased tissue regions. The wash-out of ICG was delayed for up to 72 h after intravenous injection in tissue volumes associated with disease, because ICG fluorescence was still detected in the diseased tissue 72 h after injection. In contrast, HPPH-car pharmacokinetics illustrated active uptake into diseased tissues, perhaps owing to the overexpression of LDL receptors associated with the malignant cells. HPPH-car fluorescence was not discernable after 24 h. This work illustrates the ability to monitor the pharmacokinetic delivery of NIR fluorescent dyes within tissue volumes as great as 0.5-1 cm from the tissue surface in order to differentiate normal from diseased tissue volumes on the basis of parameters obtained from the pharmacokinetic models.

In vivo and in vitro methods for evaluating airways inflammation: implications for respiratory toxicology.

The lung is frequently the target of injury for toxic exposures. Often these exposures lead to significant disease. Assessment of toxic exposures to the lung, however, may be made using both in vitro and in vivo methods. Recent advances in respiratory cell biology have made possible in vitro analyses of the interactions between airway cells and potential toxins. In addition, the lung can be sampled in vivo using bronchoscopy and bronchoalveolar lavage. This opens up the possibility of assessing potential toxins prior to the development of clinically significant disease. Together, these advancing methodologies promise new potential for the assessment and evaluation of toxic exposures to the lung.

Video-assisted evacuation of empyema is the preferred procedure for management of pleural space infections.

BACKGROUND: Empyema remains a cause of morbidity and mortality. Thoracoscopy has proved its versatility in the management of pleural space disorders. The suitability of video-assisted thoracic surgery (VATS) for decortication in the management of the fibrotic stage of empyema is unclear. METHODS: VATS evacuation of empyema and decortication was performed on seventeen patients presenting with pleural space infections. A retrospective review was performed and constitutes the basis of this report. RESULTS: VATS evacuation of empyema and decortication was successfully performed in 13 of 17 patients. Blood loss was 325 +/- 331 cc. Mean hospital stay was 18 +/- 10 days. Postoperative hospitalization was 11 +/- 7 days. Chest tubes remained in place for 7 +/- 3 days. There were no operative mortalities. CONCLUSIONS: Video-assisted evacuation of empyema and decortication is an effective modality in the management of the exudative and fibrinopurulent stages of empyema. An organized empyema should be approached thoracoscopically, but may require open decortication.