Search PubMed⌕ Search

Biomedical subjects

T F Boat

Publications and source records attributed to T F Boat.

At least 55 records · Page 3Linked to original sources

Identification of a major heparin-precipitable protein in human serum and its relationship to cystic fibrosis.

Heparin binding to serum proteins and their subsequent precipitation is reportedly increased in cystic fibrosis (CF). We have confirmed this finding for CF patients over the age of 12 [11.34 +/- 2.42 mg/ml precipitated protein for normals (n = 19) versus 17.46 +/- 4.60 mg/ml for CF patients (n = 37), P less than 0.001; 0.629 +/- 0.098 mg/ml precipitated heparin for normals versus 0.789 +/- 0.206 for CF patients, P less than 0.01]. We have also shown that patients with a variety of pulmonary diseases unrelated to CF do not show this effect. When the amounts of protein and heparin precipitated are compared with the amount of IgG found in the whole serum sample, the correlation coefficients (protein r = 0.77; heparin, 0.74; n = 81) are significant at a level of P less than 0.001. In addition, the report that young CF patients exhibit hypogammaglobulinemia prompted us to examine serum samples from CF patients and age-matched controls under the age of 12. No differences were found. To investigate the molecular basis for this effect, sera from patients with CF and from age-matched controls were precipitated with 50 mg% heparin at pH 5.57. Pellets resolubilized in 8 M urea were fractionated on DEAE-Sephadex and analyzed by double-immunodiffusion, SDS-PAGE, immunoelectrophoresis, and radial immunodiffusion. IgG constituted 55-56% of the eluted protein. When serum from all donors was fractionated by Staph A-Sepharose into IgG and non-IgG fractions, 85-89% of heparin precipitable protein was in the IgG fraction.

Adolescent↗

Mucin release from rabbit tracheal epithelium in response to sera from normal and cystic fibrosis subjects.

We have developed an assay for the release of mucous glycoproteins secreted by rabbit tracheal mucosa to study the mucus-stimulating properties of cystic fibrosis (CF) serum. Glycoproteins are labeled to equilibrium with both [35]-sulfate and [3H]-glucosamine. The relative secretory rate (RSR) of these glycoproteins is assessed after incubation with 50% (v/v) CF and control sera. Serum from all sources significantly increased the RSR for incubation times ranging from 10 min to 4 h. CF serum produced a significantly greater RSR than control serum after 10 min exposure, but not after longer exposure intervals. After 10 min, RSR for [35SO4]-glycoproteins was 3.6 +/- 0.2 in the presence of sera from healthy individuals, and 2.3 +/- 0.4 in the presence of sera from control patients with lung disease. Heterozygote RSR values were usually higher than control values, but not different than CF homozygote values. The CF serum activity was reduced by freezing and thawing. Increasing the calcium content of incubation medium did not alter serum effects. Calcium inophore A23187 did not mimic CF serum activity. High molecular weight and albumin, but not IgG, fractions from Sephadex G-200 chromatography of CF and control sera generally contained high levels of mucin-release activity. No chromatographic pattern of activity was distinctive for CF.

Adolescent↗

A comparative study of lysozyme and its secretion by tracheal epithelium.

Tracheal explants from baboon, ferret, dog, mouse, hamster, rat guinea pig, chicken, sheep, rabbit and cat were maintained in vivo for 24 to 72 hr. Bathing media were analyzed for lysozyme content. Secretory rates were compared to the rate obtained for human trachea in our earlier work. These rates ranged from 807 micrograms lysozyme/g tissue/24 hr for human trachea to 11 micrograms lysozyme/g tissue/24 hr for chicken trachea. Secretory rates for baboon, ferret dog, mouse, hamster, rat, and guinea pig tracheal lysozyme fell within this range in decreasing order. No detectable lysozyme was released from sheep, cat, or rabbit explants. Lysozyme secretion did not correlate with the presence or absence of submucosal glands. Lysozyme from laboratory animals in all cases differed with respect to electrophoretic mobility and immunochemical properties from human lysozyme. These observations provide physiological, physiochemical, and immunochemical information which will facilitate the use of lysozyme to assess secretion of macromolecules in in vitro and in vivo studies of airway epithelium.

Animals↗

Treatment and prognosis of rectal prolapse in cystic fibrosis.

Rectal prolapse occurred in 112 (18.5%) of 605 cystic fibrosis patients. In 48 patients prolapse preceded diagnosis of cystic fibrosis, but physicians (pediatricians, pediatric and general surgeons, and proctologists) rarely appreciated its importance as a symptom of this disease. Prolapses frequently cease with institution of pancreatic enzyme replacement therapy following diagnosis of cystic fibrosis. However, even when the disease remains undiagnosed, the symptom is often transient and frequently resolves at 3-5 yr of age. Prolapse occurring initially after cystic fibrosis is diagnosed rarely responds to manipulation of diet or enzyme doses. Many patients develop a method of reduction which involves voluntary abdominal, perineal, and gluteal muscles and does not require manual pressure on the prolapsed segment. Most patients do not need specific treatment for the prolapse. Surgery is rarely necessary. A sweat test should be obtained on any child who has had even a single episode of rectal prolapse.

Adolescent↗

EDTA-mediated separation of cat tracheal lining epithelium.

After specimens of cat trachea were incubated for 2 hr in 20 mM EDTA, the epithelium could easily be stripped from the mucosal surface with a dissecting needle. The epithelium was cleanly separated from its basal lamina, which remained fixed to the lamina propria. Epithelial cells were well preserved, junctional complexes were structurally intact, and there was no widening of intercellular spaces. The inferior epithelial surface was irregular, with numerous membrane-bound blebs arising from the constituent epithelial cells. Hemidesmosomes, which are found only on basal cells, were covered by a nap of fine filaments, the remnants of the filaments that normally traverse the lamina lucida. In many basal cells, cleaved hemidesmosomes were internalized, probably representing a stage in their lysosomal degradation. The basal lamina adhering to the lamina propria appeared in the transmission electron microscope as a sinuous linear density. In the scanning electron microscope, the basal lamina surface had an irregularly corrugated appearance. The basal lamina continued into the stomata of the submucosal gland ducts, which intersected the surface at an acute angle. Anchoring fibrils identical to those associated with stratified squamous epithelium were found in significant numbers on the connective tissue face of the basal lamina. Separation of tracheal tissues may provide a means whereby secretory activity and products of epithelium and submucosal glands can be individually assessed.

Animals↗

Mucous glycoproteins from cat tracheal goblet cells and mucous glands separated with EDTA.

Respiratory tract mucous glycoproteins (MGP) are secreted by goblet cells in the surface epithelium and by submucosal glands. The MGP in airway secretions collected in vivo and from airway explants in vitro represent an admixture of secretions from these sources. Incubation of cat tracheal explants in 20 mM EDTA allowed physical separation of the surface epithelium from the underlying tissues and the culture of each isolated secretory element. Separated tissues appeared morphologically intact and continued to secrete MGP. The MGP arising from the surface epithelium had more sialic acid relative to galactose and N-acetylglucosamine and appeared to be less highly sulfated, as determined by DEAE cellulose chromatography, than MGP from submucosal glands. The EDTA-mediated separation of the airway secretory elements may allow further investigation into specific secretory functions of these two epithelial elements.

Animals↗

Are measurements of urine enzymes useful during aminoglycoside therapy?

We prospectively evaluated concentrations of beta-D-galactosidase, alpha-L-fucosidase, beta-D-N-acetylglucosaminidase, and lysozyme in urine from normal subjects, ambulatory patients with cystic fibrosis (CF), and CF patients with previously normal renal function who were receiving intravenous aminoglycoside (AG) therapy. Enzyme activities were generally low or negligible in subjects not receiving AG. Enzymuria was documented during 12 of 13 AG treatment courses and most frequently involved beta-D-N-acetylglucosaminidase excretion. In nine courses, enzymuria occurred in the absence of proteinuria or elevations of blood urea nitrogen and serum creatinine. In three courses attended by enzymuria and evidence of nephrotoxicity, neither the time of appearance nor the magnitude of enzymuria was different from that of nonnephrotoxic patients. In two of these three treatment courses, enzymuria preceded clinical evidence of nephrotoxicity of 16 and 5 days, and in the third course enzymuria and elevation of blood urea nitrogen and serum creatinine occurred simultaneously. We conclude that enzymuria is not a reliable predictor of nephrotoxicity due to AG in CF patients and is not an indication of discontinue AG therapy.

Acetylglucosaminidase↗

Psychosocial functioning of children with cystic fibrosis.

The adjustment of children with cystic fibrosis as rated by parents and teachers was compared to that of physically healthy siblings, normal children, and other chronically ill children. The findings indicated that children with cystic fibrosis achieved an age-adequate level of adjustment at home and school. Adjustment was largely unrelated to the severity of cystic fibrosis. As a group, chronically ill children had less adequate adjustment as rated by parents. However, severe adjustment problems were relatively rare. These findings are consistent with a growing body of literature which suggests that children with cystic fibrosis can cope reasonably well with life tasks and that emotional disturbance is not an inevitable consequence of the disease. Future studies of the cystic fibrosis population should study factors which differentiate adjusted from maladjusted children.

Adolescent↗

Heart failure in cystic fibrosis. Treatment and prognosis of cor pulmonale with failure of the right side of the heart.

Failure of the right side of the heart with cardiac dilation and fluid retention occurred in 55 of 170 patients who died of cystic fibrosis; six patients survive. All had severe hypoxia, but 24% had normal PaCO2. Cardiac catheterization showed high mean pulmonary artery pressure and resistance. Pulmonary artery wedge pressure was greater than 12 mm Hg in 40% of the patients. Mean survival was eight months. Male survival was significantly better than female survival. Digitalis treatment was of no clear benefit. Tolazoline hydrochloride was also ineffective. Recent medical advances have not substantially affected prognosis.

Adolescent↗

Biochemistry of airway mucus secretions.

Tracheobronchial secretions are a complex mixture of secretory fluids derived from sources within the lung. Important constituents include the mucous glycoproteins, other secretory proteins, serum proteins, lipids, salts; water makes up 95% of mucus by weight. These secretions form two phases at the epithelial surface: a mucous gel and an aqueous layer (periciliary fluid). Polymerization and aggregation of mucous glycoproteins create the gel matrix. Other macromolecules such as lysozyme, albumin, and immunoglobulin A also may participate in the process of gelation. Intermolecular forces contributing to gelation include disulfide bonding, sugar-sugar interactions between adjacent glycoproteins, and ionic interactions between the glycoprotein anionic groups (sialic acid carboxyl and sulfate) and cationic components in the secretions. Respiratory tract mucous glycoproteins are large, extended molecules, which have a high carbohydrate content. They are polydisperse, with variation occurring largely in the content of sulfated sugars and sialic acid. Factors such as cell of origin, chronic lung disease, and pharmacologic effects influence the density of these anionic (acidic) groups. Variation in acidic properties may influence the physical and virus-binding properties of mucus. Little information is available concerning the biosynthetic mechanisms in airway epithelium through which these variations are effected.

Animals↗

Evidence against a specific effect of serum from patients with cystic fibrosis on sodium-dependent glucose transport in the rat jejunum.

Sera from patients with cystic fibrosis of the pancreas (CF) and normal human sera were assayed for the ability to inhibit sodium-dependent glucose transport in rat brush-border membrane vesicles. Fresh CF and age- and sex-matched control sera were both inhibitory when compared to physiologic saline. The inhibition by CF serum was 44 +/- 13% (mean +/- SD) at a final serum concentration of 6.7%, 67 +/- 34% at 10% serum, and 68 +/- 28% at 20% serum. The ratio of the inhibition of CF sera compared to that of control sera was 1.00, 0.78, and 0.93 at 6.7, 10, and 20% serum concentrations, respectively. Although a slightly greater inhibition by CF serum was observed at a concentration of 10%, this is probably not significant because no difference could be detected at a concentration of 20% serum. Glucose transport in the presence of serum was sensitive to phlorizin indicating that the residual glucose transport was proceeding by the sodium-dependent glucose transport system. These findings suggest that CF serum does not specifically inhibit the sodium-dependent glucose transport system. The intravesicular space accessible to glucose was reduced in the presence of CF or control serum. Fresh CF serum was 1.4 times more effective than fresh control serum (P less than 0.01). The presence of substantial vesicle-shrinking activity in control serum indicates that this activity cannot be considered specific for CF.

Animals↗