A morphologic study of long-term retention of fluorocarbon after liquid ventilation.

STUDY OBJECTIVES: To determine how long perfluorinated hydrocarbons remain in the lung after they are used for lung ventilation in dogs, and to determine if residual perfluorinated hydrocarbons cause structural alteration or an inflammatory reaction of the lung. DESIGN: Adult dogs were anesthetized and received ventilation with oxygenated perfluorinated hydrocarbon liquid. Morphologic studies of tissue from the lungs of these dogs were performed at intervals of a few minutes to 10 years after reconversion to breathing gas. SETTING: University College of Medicine. PARTICIPANTS: Adult mongrel and beagle dogs. INTERVENTIONS: Anesthetized adult dogs breathed oxygenated liquid fluorocarbons for 1 h and then were reconverted to breathing air. Three fluorocarbons, FX-80 (C(8)F(16)O; 3M Company; St. Paul, MN), Caroxin-D (C(10)F(22)O(2); P-1D; Allied Chemical Company; Morristown, NJ), and Caroxin-F (C(9)F(20)O; P-12F; Allied Chemical Company), were used. Morphologic studies of the lungs of these animals were performed immediately after restoration of air breathing and at intervals for up to 10 years. Not all animals were studied at each time interval. MEASUREMENTS AND RESULTS: A transient, acute inflammatory reaction was followed by a massive influx of macrophages, which were at first intra-alveolar and later interstitial, especially around vessels and bronchioles. Fluorocarbons remained in the lung in diminishing amounts for at least 5 years, as evidenced by persistent vacuolated macrophages in the alveoli, interstitium, and hilar lymph nodes; fluorocarbon was also detected in these tissues by chemical assays. In no case was there fibrosis or any other structural alteration associated with the residual fluorocarbon, which suggests that it was inert. At 10 years, no evidence of residual fluorocarbon was seen morphologically.

Pulmonary effects of chronic exposure to liposome aerosols in mice.

Administering liposome-encapsulated drugs by aerosols could be a feasible way of targeting drugs to the lung, specifically to pulmonary alveolar macrophages (AM). In the mouse model, we characterized uptake of carboxyfluorescein- (CF-) labeled liposomes by AM in vivo after acute inhalation of liposome aerosols, and the effects of chronic exposure to liposome aerosols on lung histology and AM function. Mice were placed in a nose-only exposure module and exposed to liposome or saline aerosols for 1 h per day, 5 days per week, for 4 weeks. Five mice of both the experimental and control groups were removed weekly and their lungs examined. Liposomes were made from hydrogenated soy phosphatidylcholine (HSPC) at 50 mg/mL. In vivo uptake of liposomes by AM was documented by fluorescence microscopy and flow cytometry of bronchoalveolar lavage (BAL). A consistent amount of 1-3 micrograms of lipid inhaled per dosing per mouse was estimated from fluorescence measurements. Addition of Triton X-100 to BAL caused a significant increase in fluorescence intensity, indicating that liposomes remained intact in the lung for a period of time. The chronic inhalation study showed no histologic changes of the lung or untoward effects on the general health or survival of animals. AM phagocytic function, intracellular killing, and fatty acid composition were not affected. Transmission electron microscopy and morphometry (computerized image analysis) of AM likewise showed no alterations as a result of the treatment. It was concluded that AM uptake of liposomes delivered by aerosol was operant in vivo. This finding validates the concept of alveolar macrophage-directed delivery of liposome-encapsulated agents to the lung via inhalation. It was also concluded that chronic liposome aerosol inhalation in mice produced no untoward effects on survival, histopathology, and macrophage function. These data confirm and extend prior findings regarding the functional and morphologic interactions of liposomes with AM in vitro (Gonzalez-Rothi et al., Exp. Lung Res. 17:687-705, 1991).

Effects of cardiopulmonary bypass on pulmonary leukostasis and complement activation.

We measured white blood cell counts and complement component (C3a, C4a, and C5a) and prostacyclin levels, and studied lung biopsy specimens, in 16 patients undergoing cardiopulmonary bypass and compared them with four patients undergoing other pulmonary procedures. Bypass caused no significant elevation in peripheral venous white blood cell counts. Higher counts were present in the right atrium compared with the left atrium. Patients who underwent bypass had elevated complement component and prostacyclin concentrations before operation and these levels increased further during operation. Trapping of polymorphonuclear leukocytes occurred in pulmonary alveolar capillaries and venules after bypass. We conclude that bypass activates complement components primarily of the alternative pathway and leads to increased blood prostacyclin levels. These changes are accompanied by polymorphonuclear leukocyte accumulation in the lungs and may be important in initiation of the adult respiratory distress syndrome in these patients.

Aspergillus panophthalmitis complicating treatment of pterygium.

A 58-year-old woman lost her left eye due to Aspergillus panophthalmitis four months after excision of a pterygium. The patient had received postoperative beta radiation and developed a scleral ulcer in the area of treatment from which no organisms could be cultured on two occasions. Because of the difficulty of diagnosing superficial mycotic infections of the eye, and because the treatment of so-called radiation scleritis may worsen fungal infections, ophthalmologists need to be aware of the potential infectious complications associated with the treatment of pterygia.

Corneal amyloidosis associated with keratoconus.

Nodular, gray-white, central corneal opacities which extended from the subepithelial zone through the anterior four fifths of the stroma developed in a 50-year-old man with a longstanding history of hard contact lens wear for keratoconus. Results of histopathologic analysis of the corneal button obtained at the time of penetrating keratoplasty disclosed that the opacities were composed of amyloid. Corneal amyloidosis is rarely found in association with keratoconus. Although there were some similarities in the pattern of amyloid deposition to that seen in primary familial amyloidosis of the cornea, the authors believe that their patient is more likely to have had a secondary amyloidosis. Corneal amyloidosis should be considered in keratoconus patients with development of unusual forms of central corneal opacification.

Amiodarone pulmonary toxicity presenting as bilateral exudative pleural effusions.

Therapy with the antiarrhythmic drug amiodarone has been associated with drug-related side effects. In addition to pulmonary fibrosing alveolitis, anecdotal reports have alluded to incidental pleural involvement associated with amiodarone. We describe an unusual manifestation of amiodarone-induced pulmonary toxicity in a patient with bilateral exudative pleural effusions and toxic involvement of other organs. We review amiodarone-associated pleural reactions reported in the literature.

Mycobacterium avium-intracellulare corneal ulcer.

A healthy 28-year-old man developed a slowly progressive corneal ulcer 21 months after an episode of corneal trauma. Acid-fast bacilli were identified in corneal scrapings, and the causative organism was identified as Mycobacterium avium-intracellulare. Medical treatment with topical amikacin and oral rifampin was ineffective, and a therapeutic penetrating keratoplasty was necessary to cure the infection. To the best of our knowledge, this is only the second reported case of a corneal infection caused by a slow-growing nontuberculous mycobacterium (Runyon groups I, II, and III) and the first caused by M. avium-intracellulare. Slowly growing nontuberculous mycobacteria should be considered among those organisms that cause corneal infection, especially in cases characterized by a protracted course and lack of response to conventional antimicrobial therapy.

Evaluation of anti-inflammatory agents using a model of granuloma formation evoked by divinyl copolymer beads in the mouse lung.

We have developed and quantitated a reproducible standardized granulomatous inflammatory reaction using divinyl copolymer beads. Approximately 10000 gas sterilized beads (43-53 micron in diameter) are injected into the tail veins of mice and embolize to the lungs where they evoke granuloma formation which is maximal at 48 h. The anti-inflammatory effects of both steroidal and nonsteroidal agents, namely, bacterial levan, hydrocortisone acetate, polyanetholsulfonate, indomethacin, acetylsalicylic acid, ellagic acid, and aminophylline were determined by comparing granuloma size in treated animals with those in untreated controls. Granulomas in paraffin sections were traced on the ground glass screen of a light microscope and the area of each granuloma measured with a digitizer-computer programmed to prepare histograms and merge data from replicate experiments. Of the agents tested, the greatest reductions in granuloma size occurred after treatment with bacterial levan (71%), hydrocortisone (70%), polyanetholsulfonate (58%), and indomethacin (55%).

Solitary eosinophilic granuloma of the lateral orbital wall.

Two children (aged 18 and 23 months at the initial examinations) were each ultimately found at surgery to have a solitary eosinophilic granuloma of the lateral orbital wall. Both patients had a symptomatic period of six weeks during which time other diagnoses were considered: bacterial preseptal cellulitis and mumps dacryoadenitis in the first case and traumatic recurrent orbital hematoma in the second. Diagnostic difficulties stemmed from confusing features in their histories, as well as the location of the lesion and the deceptively minimal swelling relative to the actual size of the lesion. Follow-up ten and 18 months after curettage of the two lesions showed no recurrence or evidence of systemic involvement. Although most reported cases describe the orbital frontal bone as the site of origin in the orbit, our cases demonstrated that unifocal eosinophilic granuloma may occur in the lateral wall of the orbit.

Assessment of tissue reactions to biomaterials: a model system using the foreign body response in the mouse lung to intravenously injected divinyl copolymer beads.

We have developed a reproducible model of granuloma formation in the mouse lung using a narrow size range (45-53 micron) of divinyl benzene copolymer beads as a standard test material. Approximately 10,000 beads are given by intravenous injection into the tail veins of mice whence they embolize to the lung and incite granuloma formation. This delivery system eliminates the superimposed inflammatory reaction due to trauma that occurs when materials are directly implanted at the test site by surgical incision. Granuloma size was quantitated at intervals from 3 h to 6 weeks by tracing mid-bead granuloma areas on the ground glass screen of a light microscope at a known magnification and measuring the areas with a digitizer interfaced with a microcomputer programmed to prepare histograms and to merge data from replicate experiments. At 3 h only a few polymorphonuclear leukocytes could be observed adhering to the beads. At 48 h, the time of maximum granuloma size (mean area = 7501 micron2), the granulomas consisted of both polymorphonuclear and mononuclear leukocytes. After 6 weeks, the granulomas were smaller, composed predominantly of mononuclear leukocytes and had a mean area of 2893 micron2. This model system allows the analysis of a large number of measurements, is reproducible, and provides a useful method for comparing the hosts' inflammatory response to a variety of potential biomaterials, as well as for determining the effectiveness of antiinflammatory drugs.

Biochemical indices of cyclophosphamide-induced lung toxicity.

Cyclophosphamide (CP) requires metabolic activation for its therapeutic action, and this metabolism results in the formation of two toxic metabolites, acrolein (ACR) and phosphoramide mustard (PM). To determine which metabolite is responsible for CP-induced lung injury, biochemical indices of toxicity and histopathologic changes in the lungs of CP-, ACR-, or PM-treated rats were evaluated. Experimental rats were given 200 mg kg-1 day-1 CP, 5 mg kg-1 day-1 ACR, or 50 mg kg-1 day-1 PM for 1 to 3 days, or were given 100 mg/kg CP for 1 day; control rats received vehicle alone for 1 to 3 days. Twenty-four hr after the last treatment the lungs were analyzed for (a) microsomal NADPH cytochrome c reductase and aniline hydroxylase activities; (b) microsomal lipid peroxide formation; and (c) glutathione content. In rats given 200 mg/kg CP, NADPH cytochrome c reductase and aniline hydroxylase activities decreased 66% (p less than 0.001) and 40% (p less than 0.001), respectively. Lipid peroxidation was increased 100 to 200% (p less than 0.001), and glutathione content was increased 60 to 70% (p less than 0.001). Similar but smaller changes were observed in the lungs of rats given 100 mg/kg CP. In rats given ACR, NADPH cytochrome c reductase and aniline hydroxylase activities decreased 66% (p less than 0.001) and 45% (p less than 0.001), and glutathione content increased 38% (p less than 0.05). In rats given PM, none of the biochemical variables examined were significantly altered. Phenobarbital and SKF 525-A prevented CP-induced biochemical alterations. Despite CP-induced biochemical alterations, no significant light microscopic changes were observed in the lungs. Alterations in lung mixed-function oxidase activity, GSH content, and microsomal lipid peroxide formation are early biochemical indices of CP-induced lung toxicity, and are due at least in part to the reactive metabolite ACR.

Chromobacterium violaceum infection of the eye. A report of two cases.

We report what we believe to be the first two known cases of Chromobacterium violaceum infection of the eye. One patient had conjunctivitis as the initial manifestation of an ultimately fatal infection. In the second patient, who suffered from chronic granulomatous disease of childhood, orbital cellulitis developed as part of a disseminated C violaceum infection from which he subsequently recovered. Infections caused by C violaceum may involve the eye and orbit. These infections are frequently fatal, but early recognition and aggressive treatment may result in a higher cure rate.

Intrastromal noninflammatory bacterial colonization of a corneal graft.

Progressive branching, needlelike stromal opacities were observed within a corneal transplant. Analysis of the corneal button by light microscopy and transmission electron microscopy disclosed a localized epithelial ingrowth into the stroma at a suture tract accompanied by intrastromal pockets of gram-positive cocci extending across the cornea. No inflammatory reaction was found in the areas of bacterial colonization. To our knowledge, noninflammatory bacterial colonization of the stroma of a corneal transplant has not been previously described.

Histopathology of meibomian gland dysfunction.

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

Intracranial spread of squamous carcinoma along the trigeminal nerve.

Two patients with intracranial dissemination of squamous carcinoma along the trigeminal nerve had facial dysesthesias mistakenly diagnosed as tic douloureux. In one case, tumor originated in the skin of the lateral canthus and spread along an orbital nerve to involve the cavernous sinus and Gasserian ganglion. In the other, the primary site was the retromolar trigone, with preponderantly deep intraosseous growth. Perineural spread occurred along the inferior alveolar nerve to eventually involve the facial and the ocular motor nerves. Such neurotropic spread of tumors is unfamiliar to many clinicians, yet early diagnosis may be life-saving. If intracranial foramina have not been transgressed, surgery and radiotherapy have been curative; otherwise, treatment is largely palliative. Adequate initial treatment of the primary lesion would seem to be the best preventive measure. Treatment of recurrent lesions should include consideration of neural invasion.

Potentiation of bleomycin toxicity by oxygen.

The clinical usefulness of bleomycin is limited by pulmonary toxicity. Recent clinical observations indicate that the pulmonary toxicity is potentiated in patients who are exposed to elevated but nontoxic concentrations of O2. We studied the interactions of O2 and bleomycin using a murine model. Mice were divided into two groups. One group was continuously exposed to 40% O2 at 1 atmosphere while the other group breathed compressed room air. The elevated O2 concentration alone was not toxic to animals. Mice in each group received either 40 mg/kg of bleomycin or normal saline twice a week sc. Median survival of mice receiving bleomycin was shortened from 8.24 to 4.35 weeks when the animals were maintained on 40% O2 (P = 0.0001). We conclude that exposure to a nontoxic but elevated O2 concentration can potentiate the toxic effects of bleomycin.

Tracheal mucosal damage after aspiration. A scanning electron Microscope study.

Aspiration of gastric contents causes severe pneumonitis, but the effects of such aspiration on the large airways have not been well studied. To evaluate the effects of gastric contents on the tracheal mucosa, 63 healthy A/J mice were anesthetized and aspirated either sterile saline (pH, 5.9) (Group I), hydrochloric acid (pH, 1.5) (Group II), canine gastric juice (pH, 1.5) (Group III), or canine gastric juice (pH, 5.9) (Group IV). Tracer studies showed that the average amount aspirated was 15% of the administered dose. Animals from each group were killed by cervical dislocation at 1, 6, 24, 48, and 72 h and 7 days after aspiration. Examination of the tracheas by scanning electron microscopy revealed normal mucosa in all Group I animals. Tracheas from Group II animals killed between 6 and 48 h after aspiration showed desquamation of the superficial cell layer with complete loss of ciliated and nonciliated cells. Regeneration was noted at 3 days with complete recovery by 7 days. Tracheas from Group III animals had similar changes but regeneration was delayed, whereas those from Group IV had mild desquamation with delayed regeneration. The lungs of group I animals were normal, and those of animals in Group II through IV showed only small widely separated areas of inflammation. We conclude that (1) gastric contents cause marked damage to the tracheal mucosa even when the amount aspirated is too small to induce a clinically significant pneumonia, (2) damage is more severe when the pH of the gastric content is low, and (3) gastric juice may contain substances that delay healing.