Complementary Role of GlcNAc6ST2 and GlcNAc6ST3 in Synthesis of CL40-Reactive Sialylated and Sulfated Glycans in the Mouse Pleural Mesothelium.

Sialyl 6-sulfo Lewis X (6-sulfo sLeX) and its derivative sialyl 6-sulfo N-acetyllactosamine (LacNAc) are sialylated and sulfated glycans of sialomucins found in the high endothelial venules (HEVs) of secondary lymphoid organs. A component of 6-sulfo sLeX present in the core 1-extended O-linked glycans detected by the MECA-79 antibody was previously shown to exist in the lymphoid aggregate vasculature and bronchial mucosa of allergic and asthmatic lungs. The components of 6-sulfo sLeX in pulmonary tissues under physiological conditions remain to be analyzed. The CL40 antibody recognizes 6-sulfo sLeX and sialyl 6-sulfo LacNAc in O-linked and N-linked glycans, with absolute requirements for both GlcNAc-6-sulfation and sialylation. Immunostaining of normal mouse lungs with CL40 was performed and analyzed. The contribution of GlcNAc-6-O-sulfotransferases (GlcNAc6STs) to the synthesis of the CL40 epitope in the lungs was also elucidated. Here, we show that the expression of the CL40 epitope was specifically detected in the mesothelin-positive mesothelium of the pulmonary pleura. Moreover, GlcNAc6ST2 (encoded by Chst4) and GlcNAc6ST3 (encoded by Chst5), but not GlcNAc6ST1 (encoded by Chst2) or GlcNAc6ST4 (encoded by Chst7), are required for the synthesis of CL40-positive glycans in the lung mesothelium. Furthermore, neither GlcNAc6ST2 nor GlcNAc6ST3 is sufficient for in vivo expression of the CL40 epitope in the lung mesothelium, as demonstrated by GlcNAc6ST1/3/4 triple-knock-out and GlcNAc6ST1/2/4 triple-knock-out mice. These results indicate that CL40-positive sialylated and sulfated glycans are abundant in the pleural mesothelium and are synthesized complementarily by GlcNAc6ST2 and GlcNAc6ST3, under physiological conditions in mice.

Structural heteropolysaccharides as air-tight sealants of the human pleura.

Pulmonary "air leaks," typically the result of pleural injury caused by lung surgery or chest trauma, result in the accumulation of air in the pleural space (pneumothorax). Air leaks are a major source of morbidity and prolonged hospitalization after pulmonary surgery. Previous work has demonstrated structural heteropolysaccharide (pectin) binding to the mouse pleural glycocalyx. The similar lectin-binding characteristics and ultrastructural features of the human and mouse pleural glycocalyx suggested the potential application of these polymers in humans. To investigate the utility of pectin-based polymers, we developed a simulacrum using freshly obtained human pleura. Pressure-decay leak testing was performed with an inflation maneuver that involved a 3 s ramp to a 3 s plateau pressure; the inflation was completely abrogated after needle perforation of the pleura. Using nonbiologic materials, pressure-decay leak testing demonstrated an exponential decay with a plateau phase in materials with a Young's modulus less than 5. In human pleural testing, the simulacrum was used to test the sealant function of four mixtures of pectin-based polymers. A 50% high-methoxyl pectin and 50% carboxymethylcellulose mixture demonstrated no sealant failures at transpleural pressures of 60 cmH2 O. In contrast, pectin mixtures containing 50% low-methoxyl pectin, 50% amidated low-methoxyl pectins, or 100% carboxymethylcellulose demonstrated frequent sealant failures at transpleural pressures of 40-50 cmH2 O (p < 0.001). Inhibition of sealant adhesion with enzyme treatment, dessication and 4°C cooling suggested an adhesion mechanism dependent upon polysaccharide interpenetration. We conclude that pectin-based heteropolysaccharides are a promising air-tight sealant of human pleural injuries. © 2018 Wiley Periodicals, Inc. J. Biomed. Mater. Res. Part B, 2018. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 799-806, 2019.

Functional Mechanics of a Pectin-Based Pleural Sealant after Lung Injury.

Pleural injury and associated air leaks are a major influence on patient morbidity and healthcare costs after lung surgery. Pectin, a plant-derived heteropolysaccharide, has recently demonstrated potential as an adhesive binding to the glycocalyx of visceral mesothelium. Since bioadhesion is a process likely involving the interpenetration of the pectin-based polymer with the glycocalyx, we predicted that the pectin-based polymer may also be an effective sealant for pleural injury. To explore the potential role of an equal (weight%) mixture of high-methoxyl pectin and carboxymethylcellulose as a pleural sealant, we compared the yield strength of the pectin-based polymer to commonly available surgical products. The pectin-based polymer demonstrated significantly greater adhesion to the lung pleura than the comparison products (p < 0.001). In a 25 g needle-induced lung injury model, pleural injury resulted in an air leak and a loss of airway pressures. After application of the pectin-based polymer, there was a restoration of airway pressure and no measurable air leak. Despite the application of large sheets (50 mm2) of the pectin-based polymer, multifrequency lung impedance studies demonstrated no significant increase in tissue damping (G) or hysteresivity (η)(p > 0.05). In 7-day survival experiments, the application of the pectin-based polymer after pleural injury was associated with no observable toxicity, 100% survival (N = 5), and restored lung function. We conclude that this pectin-based polymer is a strong and nontoxic bioadhesive with the potential for clinical application in the treatment of pleural injuries.

Relationship of chemical structure and anti-inflammatory activity of dihydrocorynantheol and its analogues.

BACKGROUND: Dihydrocorynantheol (DHC) is an alkaloid compound isolated from Esenbeckia leiocarpa Engl. that has demonstrated anti-inflammatory properties in experimental models. The aim of this study was to investigate whether the modification of the chemical structure of DHC could alter its anti-inflammatory effect in a mouse model of pleurisy induced by carrageenan. METHODS: DHC was isolated from Esenbeckia leiocarpa Engl. Capillary electrophoresis, physical characteristics, spectral data produced by infrared analysis and nuclearmagnetic resonance ((1)H and (13)C), and mass spectrometry analysis were used to identify and elucidate DHC structure. The DHC compound was subjected to chemical structural modifications by nucleophilic substitution reactions, yielding five analogous compounds: acetyl (1), p-methylbenzoyl (2), benzoyl (3), p-methoxybenzoyl (4) and p-chlorobenzoyl (5). Swiss mice were used throughout the experiments. Pro-inflammatory parameters leukocyte migration, exudate concentrations and myeloperoxidase (MPO) activity were quantified in the fluid leakage from the mouse pleural cavities at 4 h after pleurisy induction. RESULTS: DHC and its analogues acetyl, p-methylbenzoyl, benzoyl, p-methoxybenzoyl and p-chlorobenzoyl inhibited total and differential leukocyte migration and MPO activity (p < 0.05). Only DHC significantly decreased the exudate concentrations (p < 0.01). CONCLUSIONS: DHC was more effective than its analogues as an anti-inflammatory agent in the mouse model of pleurisy induced by carrageenan. We did not determine what physicochemical modifications altered the anti-inflammatory effect of DHC, but this effect may be due to the modifications on the hydroxyl group at carbon 17 of the DHC.

Anti-inflammatory effect of magnolol, isolated from Magnolia officinalis, on A23187-induced pleurisy in mice.

In the present study, A23187-induced pleurisy in mice was used to investigate the anti-inflammatory effect of magnolol, a phenolic compound isolated from Chinese medicine Hou p'u (cortex of Magnolia officinalis). A23187-induced protein leakage was reduced by magnolol (10 mg kg-1, i.p.), indomethacin (10 mg kg-1, i.p.) and BW755C (30 mg kg-1, i.p.). A23187-induced polymorphonuclear (PMN) leucocyte infiltration in the pleural cavity was suppressed by magnolol and BW755C, while enhanced by indomethacin. Like BW755C, magnolol reduced both prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) levels in the pleural fluid of A23187-induced pleurisy, while indomethacin reduced PGE2 but increased LTB4 formation. In the rat isolated peripheral neutrophil suspension, magnolol (3.7 microM) and BW755C (10 microM) also suppressed the A23187-induced thromboxane B2 (TXB2) and LTB4 formation. These results suggest that magnolol, like BW755C, might be a dual cyclo-oxygenase and lipoxygenase inhibitor. The inhibitory effect of magnolol on the A23187-induced pleurisy is proposed to be, at least partly, dependent on the reduction of the formation of eicosanoids mediators in the inflammatory site.

An in vivo model for screening peptidomimetic inhibitors of gelatinase A.

Gelatinase A, a matrix metalloproteinase, is frequently associated with human solid tumors, and its secretion and activation in the tumor milieu is considered important in the process of angiogenesis, invasion, and metastasis. Consequently, metalloproteinase inhibitors may be of value in the therapy of cancer as well as other disease states involving tissue remodeling and release of biologically active peptide/protein by proteolytic cleavage. Here we describe the development of a rapid screening assay for in vivo activity of peptidomimetic inhibitors of gelatinase A that involves assessment of inhibition of an enzyme-substrate reaction in a circumscribed body compartment, the mouse pleural cavity. As examples of the utility of this assay, in vivo activity of the aryl sulfonamide, sulfamyl urea, morpholino and carboxylic acid functionality at the P3' position of a series of hydroxamic acid inhibitors was examined after administration both intraperitoneally (ip) (to approximate systemic administration) and orally. For up to 2 h after ip administration, all inhibitors tested showed marked activity (> 90% inhibition) at 17 mumol/kg (approximately 10 mg/kg). This activity declined in a dose-responsive manner to insignificant levels at 0.67 mumol/kg (approximately 0.4 mg/kg). Aryl sulfonamides showed significant inhibition (> 50%) for up to 7 h after administration. A higher dosage (136 mumol/kg, approximately 80 mg/kg) was required to reveal oral activity, which was observed only with morpholino compounds (> 50% inhibition). Thus, the model described may be of value in the identification of orally active gelatinase A inhibitors.

Influence of volume on the spread of local anesthetic-methylene blue solution after injection for intercostal block.

The purpose of this study was to evaluate the influence of the volume of methylene blue-local anesthetic on the spread of the injectate along the costal pleura. Twenty patients undergoing elective thoracotomy were studied. Twelve patients received intercostal nerve injection with 10 mL of 0.5% bupivacaine with methylene blue (10-mL group), and eight patients received 5 mL of 0.5% bupivacaine with methylene blue (5-mL group). The area of spread of the methylene blue was measured after the pleural cavity was incised. The 10-mL group had a mean area of spread of 51.1 cm2 as opposed to 17.6 cm2 for the 5-mL group (P less than 0.05). In the 10-mL group, eight patients had bupivacaine-methylene blue spread to two intercostal spaces, three patients to three intercostal spaces, and one patient to four intercostal spaces. In the 5-mL group, seven patients had bupivacaine methylene blue spread confined to one intercostal space and one patient to two intercostal spaces. We conclude that a potential anatomic space exists between the costal pleura and the internal intercostal muscle and that the spread of local anesthetic after intercostal nerve block injection is volume dependent.

[Changes in the lungs and pleura following chemoembolization of liver tumors with mitomycin-lipiodol]. / Veränderungen der Lunge und Pleura nach Chemoembolisation von Lebertumoren mit Mitomycin-Lipiodol.

The authors performed 68 liver embolizations in 51 patients. As selectively as possible, Lipiodol, to block the capillary bed, and a chemotherapeutic agent were injected into the liver tumors. A CT performed 24 hours after treatment showed the distribution of the contrast medium which is also an indicator of the distribution of the chemotherapeutic agents. It was found that the contrast medium had accumulated not only in the liver but also in the lungs. Here, four different degrees of accumulation were found, according to the amount of Lipiodol used. Embolization of the liver thus involves potential hazards for the lungs, such as microembolisms, pneumonia, and toxic effects of the chemotherapeutic agents.

Penetration of imidazole 2-hydroxybenzoate (ITF 182) into experimentally inflamed pleural and knee joint exudates.

The penetration of the two components of imidazole 2-hydroxybenzoate (ITF 182), imidazole and salicylate, into inflamed sites induced by intrapleural injection of carrageenin in the rat and by a urate-cotton pellet implantation in the knee joint of the rabbit is studied. The results obtained show that the two components of the salt penetrate rapidly the inflamed sites and display different kinetic profiles: imidazole diffuses throughout inflamed and non-inflamed fluids without any specific localization, salicylate shows preferential localization in inflamed fluids and remains longer than imidazole.