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Biomedical subjects

J U Balis

Publications and source records attributed to J U Balis.

At least 37 records · Page 2Linked to original sources
PubMed1985

Distribution and subcellular localization of surfactant-associated glycoproteins in human lung.

Human surfactant contains lung-specific, high molecular weight glycoproteins which are composed of disulfide-linked 34-kilodalton peptide subunits. We prepared antibodies to both isolated HMW glycoproteins and 34-kilodalton peptides and tested the antisera for specificity with immunochemical procedures. In the present study we have investigated the cellular distribution and subcellular localization of these glycoproteins in surgically excised human lung tissue with or without type II cell hyperplasia. An immunoperoxidase technique was used, and cytoplasmic staining reflecting labeling with antibodies to either high molecular weight glycoproteins or the 34-kilodalton peptide subunits was consistently observed in normal type II cells, Clara cells, and some alveolar macrophages and was more intense and diffuse in hyperplastic type II cells. The ultrastructural localization of surfactant-associated glycoproteins was investigated using the periodate-lysine-paraformaldehyde fixative and a peroxidase-labeled antibody technique. In both normal and proliferating type II cells the staining was localized in the rough endoplasmic reticulum, perinuclear cisternas, vesicles of the Golgi complex, vesicles and lamellar membranes of the multivesicular bodies, and some multivesicular body-lamellar body forms. In addition, staining was frequently found in peripheral portions of partially preserved lamellar bodies including those at the stage of secretion, as well as in association with of alveolar tubular myelin. Labeling was also observed in the rough endoplasmic reticulum of Clara cells. We conclude that antibodies against human surfactant-associated glycoproteins are markers for normal and regenerating type II cells, as well as for Clara cells which apparently retain limited ability to produce surfactant-associated glycoproteins independently of surfactant phospholipids. The results indicate that, in type II cells, synthesis and secretion of these glycoproteins involve the same cytoplasmic organelles that are responsible for synthesis, packaging, storage, and exocytosis of surfactant phospholipids. However, maturation of the lamellar bodies, known to be characterized by progressive accumulation of phospholipids, may not require parallel storage of surfactant-associated glycoproteins within the entire lamellar body compartment.

Aged↗
PubMed1984

Ultrastructural and immunohistochemical studies of bronchiolo-alveolar carcinoma.

A detailed ultrastructural study was made of seven cases of bronchiolo-alveolar carcinoma, and the findings were correlated with histochemical and immunohistochemical data. By electron microscopic examination all seven tumors displayed glandular differentiation, manifested by the presence of microvilli and intercellular junctions, with or without mucin production. Variable proportions of tumor cells retained ultrastructural characteristics of alveolar type II cells and Clara cells. In addition, some tumor cells revealed desmosomes and tonofilaments consistent with squamous differentiation. Immunohistochemical evaluation was carried out using a peroxidase-antiperoxidase technique and specific antibodies against surfactant high molecular weight glycoproteins, keratin proteins, IgA + secretory piece, carcinoembryonic antigen (CEA), human chorionic gonadotropin (HCG), and alpha-fetoprotein (AFP). Four tumors with type II cell-like differentiation stained with anti-surfactant glycoprotein sera. All seven tumors stained focally with anti-keratin and IgA + anti-secretory piece antibodies, and diffusely with CEA. These tumors failed to stain with antisera against HCG and AFP. It is concluded that bronciolo-alveolar carcinomas are primarily composed of cells with alveolar and bronchiolar cell differentiation. Adequate criteria were established for ultrastructural identification of tumor cells with differentiation to type II alveolar cell or Clara cell. Moreover, the findings of this study indicate that the surfactant glycoprotein marker, when present in a given tumor either diffusely or focally, is diagnostic of bronchiolo-alveolar carcinoma.

Adenocarcinoma↗
PubMed1984

Lung surfactant phospholipids in different animal species.

A comparative study of adult mammalian lung surfactants was undertaken to determine which animal species might serve as appropriate models for surfactant alterations in human lung diseases. Phosphatidylcholine (PC) comprised 80-87% of the phospholipid and contained more than 65% palmitic acid in all species studied. Phosphatidylglycerol (PG) was found to vary significantly in fatty acid composition among the species. Rabbit, dog and rat surfactant PG contained 50-60% palmitic acid, while human and cat surfactant contained much lower levels of saturated fatty acids. Both the PC and PG of all species contained 2 positional isomers of fatty acids with 16 carbons and one double bond, but the relative amounts of the unusual isomer, 16:1 delta 7, and palmitoleic acid, 16:1 delta 9, varied among the different animal species. Only cat and dog surfactant phospholipids contained 18:1 delta 5. Cat surfactant phospholipids also differed by the absence of 20:4 and the presence of small amounts of several 20- and 22-carbon fatty acids. These results explain some discrepancies found in the literature concerning surfactant composition and delineate limiting factors in extrapolating results from animal studies for the evaluation of maturation and pathological alterations in human surfactant.

Animals↗
PubMed1984

Synthesis of lung surfactant-associated glycoproteins by A549 cells: description of an in vitro model for human type II cell dysfunction.

Immunocytochemical, ultrastructural, and biochemical approaches were used in a series of in vitro and in vivo experiments designed to identify characteristic changes reflecting differentiated type II cell function of A549 cells. Monolayers of A549 cells and A549 clones were maintained in culture for up to 3 weeks. Using an immunoperoxidase (PAP) technique, we demonstrated that variable proportions of A549 cells and of cells in several A549 clones reacted specifically with antibodies to high molecular weight (greater than 400,000) human surfactant-associated glycoproteins (HSAG). The cells of one clone, A549-C12, were consistently negative for HSAG, but their lamellar bodies were similar in appearance and distribution to those found in a PAP-positive clone, A549-C11, as well as in A549 cells. In addition, both C11 and C12 clones displayed time-dependent, divergent differentiation predominantly toward type II epithelium and nonciliated bronchiolar and bronchial cells. Surfactant isolated from either C11 or C12 cells revealed reduced content of disaturated phosphatidylcholine and phosphatidylglycerol when compared to human surfactant; however, a 95,000-dalton peptide immunologically related to HSAG was identified in surfactant from C11 cells but not from the PAP-negative C12 clone. Tumor xenografts produced in athymic (nude) mice following inoculation with cells from C11 and C12 clones exhibited prominent immunoperoxidase staining involving most tumor cells. Cell lines derived from these xenografts (T-11 and T-12) were also enriched in PAP-positive cells. Immunoelectron microscopy indicated that HSAG was localized in the rough endoplasmic reticulum, multivesicular bodies (MVB), intermediate MVB-lamellar forms, and abnormal pleomorphic inclusions. Moreover, two HSAG peptides, both larger than the 34,000-dalton peptide subunit found in normal human surfactant, were present in cells and media from monolayers of the T-11 cell line. We conclude that A549 cells synthesize "defective" HSAG and that the synthesis may be modulated by host factors. The results indicate that appropriate A549 clones can be used effectively as model systems for selected type II cell dysfunctions.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed1983

Inhibition of bradykinin-induced contraction of isolated smooth muscle tissue preparations by oligopeptide thiobenzyl ester substrates for serine proteases.

Synthetic peptide substrates containing various chromophores and fluorophores have been utilized in the quantitation of serine protease activities. Recently, amino acid thiobenzyl esters containing arginine and lysine have also been used to evaluate the serine proteases. In an attempt to develop specific peptide thiobenzyl substrates, we have screened D-Pro-Phe-Arg-S-CH2-C6H5, D-Phe-Phe-Arg-S-CH2-C6H5, D-Gly-Pro-Arg-S-CH2-C6H5, and D-Val-Leu-Lys-S-CH2-C6H5 to determine the enzymatic activity of serine proteases. Since we found that D-Pro-Phe-Arg-pNA is a potent inhibitor of the bradykinin induced contractile action of isolated smooth muscle preparations such as the guinea pig ileum and rat uterus, we screened D-Pro-Phe-Arg-S-CH2-C6H5 at a 5 X 10(-5) M and found that it completely blocked the bradykinin (1 ng) induced contraction of the isolated rat uterus preparation. Other peptide thiobenzyl esters produced somewhat weaker effects, however, none of the free peptides not C6H5CH2SH, at concentrations of up to 10 microns, produced any significant contraction or inhibition of the isolated smooth muscle preparation. These observations suggest that peptide thiobenzyl esters are effective blockers of bradykinin induced contraction of the isolated smooth muscle preparations and the amino acid sequence of the peptides plays an important role in the determination of relative potency of each of these peptide derivatives. Moreover, the result of this investigation provides the basis for a new approach to further design specific inhibitors of the pharmacologic actions of biologically active peptides.

Animals↗
PubMed1982

Surfactant "apoproteins" in human amniotic fluid: an enzyme-linked immunosorbent assay for the prenatal assessment of lung maturity.

We have developed an enzyme-linked immunosorbent assay for the quantitation of human lung surfactant high--molecular weight proteins and used this assay to evaluate changes in surfactant "apoprotein" content of amniotic fluid during the last trimester of pregnancy. The amount of surfactant apoprotein in human amniotic fluid increased with advancing gestational age and correlated well with other parameters of fetal lung maturity, the lecithin:sphingomyelin ratio, and the presence of phosphatidylglycerol. The findings suggest that this test, which is relatively simple to perform, may prove useful as an additional clinical parameter for assessing fetal lung maturity and predicting more accurately fetuses at risk of developing hyaline membrane disease.

Amniotic Fluid↗
PubMed1982

Ultrastructural stereologic analysis of fetal rabbit type II alveolar epithelial cells following maternal pilocarpine treatment or fasting.

We have previously reported that subcutaneous administration of 5 mg/kg pilocarpine HCl, a muscarinic agonist, to pregnant white rabbits on days 24 through 27 of gestation results in an acceleration of fetal lung maturation. In the present study the ultrastructural differences observed within alveolar type II cells of 28-day fetuses from the pilocarpine and control groups were quantified by stereologic analysis. In addition, maturational changes occurring within the lungs of 28-day fetuses obtained from pregnant rabbits which were fasted for 7 days (days 21-28) were similarly analyzed. Stereologic analysis revealed that the fetal type II cells in the pilocarpine-treated group possessed a significantly greater volume density of lamellar inclusion bodies and rough endoplasmic reticulum and a significantly smaller volume density of glycogen than did controls. The volume density values for fetal type II cells of the fasted group were, with the exception of the Golgi apparatus, found to be intermediate between those of control and the pilocarpine-treated groups. It was also noted that a high percentage of the lamellar inclusion bodies within type II cells of the fasted group appeared morphologically abnormal, being characterized by a highly irregular outline and tightly packed lipid membranes. The results of this study substantiate and quantify our previously reported observation of accelerated maturation in pilocarpine-treated fetuses. In addition, they suggest a similar, though not as pronounced, effect of maternal fasting prior to delivery. However, the abnormal morphology of the lamellar inclusion bodies in the fasted group may reflect a qualitative change in the pulmonary surfactant produced by these fetuses.

Animals↗
PubMed1981

Isolation, characterization and localization of a 45 000 molecular weight, soluble glycoprotein from the lung in pulmonary alveolar proteinosis.

A carbohydrate-rich, water-soluble glycoprotein has been isolated in pure form from delipidated lung lavage fluid from a patient with pulmonary alveolar proteinosis, in a three-step procedure involving ion-exchange and gel filtration chromatography. The molecular weight of the glycoprotein was determined to be 45 900 by sedimentation equilibrium analysis in the analytical ultracentrifuge and 45 000 by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate, indicating a single polypeptide chain. Nearly half of the mass of the glycoprotein is comprised of carbohydrate that is contributed by 24 residues sialic acid, 23 residues N-acetylglucosamine, 6 residues N-acetylgalactosamine, 19 residues galactose, 4 residues mannose, 1 residue fucose and 1 residue glucose per mol. Unlike a number of collagen-related glycoproteins that have been isolated by others from insoluble lung contents in pulmonary proteinosis, the water-soluble glycoprotein described in the present report does not contain hydroxyproline or hydroxylysine and contains less than 10% of its amino acid residues as glycine. Using rabbit antibodies directed against our purest preparation of material and an immunoperoxidase staining procedure, the 45 000 molecular weight glycoprotein was localized to the thin film of fluid lining the surfaces of alveoli in normal human lungs.

Amino Acids↗
PubMed1981

Role of splenic red pulp in endotoxin-induced disseminated intravascular coagulation.

As an extension of our studies on vascular responses to endotoxemia, we evaluated sequential ultrastructural lesions of splenic red pulp and correlated these lesions with coagulation changes observed in rhesus monkeys following infusion with endotoxin either as a single bolus (10 mg. per kg.) or at a continuous rate of 10 mg. per kg. per hour for periods up to 16 hours. Controls included monkeys infused with Ringer's lactate solution. Progressive reactions of the splenic cords included increased phagocytic activity of macrophages in association with aggregation and degranulation of platelets and prominent fibrinous deposits characteristically abutting basement membranes of endothelial and reticular cells. The sinuses demonstrated endothelial damage, platelet-fibrin microthrombi obstructing interendothelial slits, and severe engorgement with entrapment of erythrocytes by tactoids of fibrin. The thrombotic lesions of the red pulp developed earlier than similar lesions in hepatic sinusoids, and they were accompanied by progressive thrombocytopenia and disseminated intravascular coagulation. The findings suggest that the unique microcirculation of the spleen is an early target and trigger of endotoxin-induced microthrombosis. It is proposed that phagocytosis of endotoxin by splenic phagocytic cells and associated inflammatory events result in disruption of reticular cells and endothelium leading to massive microthrombosis with breakdown of the splenic filter. In addition, rapid activation of coagulation mechanisms in the red pulp as well as liver sinusoids may promote the development of thrombocytopenia and disseminated intravascular coagulation in endotoxic shock.

Animals↗
PubMed1980

Secretory IgA is a component of rabbit lung surfactant.

Secretory IgA is a major protein component of rabbit lung surfactant purified by NaBr density gradient centrifugation from endobronchial lavage and minced lung tissue. Secretory IgA was found in both surfactant and non-surfactant fractions obtained from endobronchial lung washings. By contrast in minced-lung washings, which are not contaminated with proteins from the upper respiratory tree, secretory IgA is prominent only in the surfactant fraction. These findings indicate that in rabbit lung secretory IgA is present in the alveoli and is intimately associated with the surfactant system.

Animals↗
PubMed1980

Peritubular capillaries. A major target site of endotoxin-induced vascular injury in the primate kidney.

We have examined by light and electron microscopy the kidneys of rhesus monkeys infused either with a single bolus of endotoxin (10 mg. per kg.) or continuously at the rate of 10 mg. per kg. per hour for periods of up to 22 hours. Controls included monkeys infused with Ringer's lactate solution. Only minor morphologic changes were seen in animals receiving a bolus of endotoxin. In the animals continuously infused, sequestration of neutrophils and monocytes was observed in the peritubular capillaries and to a lesser extent in the glomeruli. These changes were associated with phagocytosis of endotoxin, occasional fibrin deposits, and extensive endothelial cell damage with focal capillary disruption. Changes found in the advanced stages included prominent interestitial edema with focal necrosis of tubular epithelium. Endothelial cell changes seen in the glomeruli were far less sever than those observed in the peritubular capillaries. Our data indicate that endothelial damage and associated events relating to the sequestration of phagocytic leukocytes primarily involve the peritubular capillaries and that this "inflammatory" process plays a basic role in the development of acute tubular necrosis during shock associated with endotoxemia.

Acute Kidney Injury↗
PubMed1979

Sequential changes of surfactant phosphatidylcholine in hyaline-membrane disease of the newborn.

Although reduced levels of lung surfactant are known to predispose to hyaline-membrane disease, the role of biochemical changes in surfactant composition has not been defined. We found that surfactant isolated from pharyngeal and tracheal aspirates of newborns with hyaline-membrane disease had a distinctly different phosphatidylcholine fatty acid composition from surfactant of control infants. Surfactant phosphatidylcholine from newborns with hyaline-membrane disease had a lower percentage of palmitic acid and higher percentages of the 18-carbon and 20-carbon fatty acids, irrespective of gestational age. Evaluation of serial aspirates for 18 days revealed that in hyaline-membrane disease the surfactant phosphatidylcholine fatty acids followed a predictable pattern of change, gradually becoming similar to those of the control group. Evaluation of surfactant from tracheal and pharyngeal aspirates effectively monitors the biochemical maturation of the surfactant system in hyaline-membrane disease.

Age Factors↗
PubMed1979

Reduced cell proliferation in fetal lung after maternal administration of pilocarpine: a scintillation autoradiographic study.

Fetuses were obtained on the 28th gestational day from pregnant New Zealand white rabbits treated daily, on the 24th through the 27th gestational day, with pilocarpine HCl, 5 mg/kg in saline, or saline alone. Lung fragments from these fetuses were incubated for two hours in medium containing 3H-thymidine. Scintillation autoradiography of 1-micrometer-thick sections of these fetal lungs revealed that the lung tissue from pilocarpine-treated fetuses had significantly lower labelled cell indices for both alveolar epithelial cells and interstitial cells. These results indicate that pilocarpine treatment promotes differentiation of immature cells in the fetal lung at the expense of cell proliferation.

Animals↗
PubMed1979

Glucocorticoid and antibiotic effects on hepatic microcirculation and associated host responses in lethal gram-negative bacteremia.

Liver changes and associated host responses were evaluated in four groups of male rats, weighing 300 +/- 20 gm., which received intravenous injection of 2.2 times 10(9) live Escherichia coli. This bolus was given either without additional treatment (group A) or prior to the following regimens: intramuscular injection of gentamicin sulfate, 5 mg. per kg. (group B); intravenous injection of methylprednisolone sodium succinate, 40 mg. per kg. (group C); and intramuscular injection of gentamicin immediately after methylprednisolone sodium succinate treatment (group D). Rats given injections of saline or methylprednisolone sodium succinate served as controls. Survival rates at 10 and 20 hours were 25 per cent and 4 per cent for group A; 44 per cent and 28 per cent for group B; 94 per cent and 70 per cent for group C; 98 per cent and 98 per cent for group D, respectively. In rats of groups A and B, killed at 1, 2, 4, and 6 hours, progressive liver changes included intravascular sequestration of rapidly degranulating leukocytes, fibrinous deposits, and platelet aggregates in sinusoids as well as in spaces of Disse adjacent to subendothelial collagen, and extensive Kupffer cell disruption in association with severe midzonal necrosis. These alterations were accompanied by progressive hypoglycemia and elevations of serum enzymes, glutamic pyruvic transaminase, lactate dehydrogenase, and glutamic oxaloacetic transaminase. Hematologic studies revealed that E. coli bacteremia results in rapid leukopenia and disseminated intravascular coagulation primarily due to activation of the intrinsic coagulation pathway. All above reactions were delayed and markedly reduced in rats treated with methylprednisolone sodium succinate. The results indicate that antibiotic treatment of lethal, Gram-negative bacteremia is effective only in conjunction with early steroid treatment. The protective effects of glucocorticoids on the liver microcirculation and polymorphonuclear leukocytes appear to play a basic role in preventing the early development of disseminated intravascular coagulation, hepatocellular necrosis, and associated major host responses, thereby attenuating lethality of gram-negative septic shock.

Animals↗