Effects of humidification on nasal symptoms and compliance in sleep apnea patients using continuous positive airway pressure.

STUDY OBJECTIVES: To evaluate the effects of humidification on nasal symptoms and compliance in sleep apnea patients using continuous positive airway pressure (CPAP). DESIGN: A randomized, crossover design was employed. SETTING: The study was conducted at two suburban community-based hospital sleep laboratories. PATIENTS: Data were collected on 38 obstructive sleep apnea patients (mean age, 44.1 years) in whom CPAP was a novel treatment. INTERVENTIONS: The interventions were heated humidity, cold passover humidity, and a washout period without humidity. MEASUREMENTS AND RESULTS: Patients were titrated with heated humidity or cold passover humidity in the laboratory and subsequently initiated on humidity. Objective compliance, self-report of factors affecting CPAP use, satisfaction with CPAP, feeling upon awakening, and daytime sleepiness were assessed at the completion of each 3-week treatment period and a 2-week washout period. Outcome measures were assessed with one-way analysis of variance followed by Scheffe post hoc comparisons. Significant main effects were observed for compliance (F2,37 = 5.2; p = 0.008), satisfaction with CPAP (F2,37 = 4.5; p = 0.01), and feeling refreshed on awakening (F2,37 = 4.4; p = 0.02). A significant decrease in daytime sleepiness was observed between baseline and each of the conditions (F3,37 = 55.5; p<0.0001), but Epworth sleepiness scale scores did not differ between conditions (all p values >0.56). CPAP use with heated humidity (5.52+/-2.1 h/night) was greater than CPAP use without humidity (4.93+/-2.2 h/night; p = 0.008). Compliance differences were not observed between CPAP use with cold passover humidity and CPAP use without humidity. Patients were more satisfied with CPAP when it was used with heated or cold passover humidity (p< or =0.05). However, only heated humidity resulted in feeling more refreshed on awakening (p<0.05). No significant differences were observed among the three groups on the global adverse side effect score (F2,37 = 2.5; p = 0.09). Specific side effects such as dry mouth or throat and dry nose were reported less frequently when CPAP was used with heated humidity compared to CPAP use without humidity (p<0.001). CONCLUSIONS: Compliance with CPAP is enhanced when heated humidification is employed. This is likely due to a reduction in side effects associated with upper airway symptoms and a more refreshed feeling upon awakening. Compliance gains may be realized sooner if patients are started with heated humidity at CPAP initiation.

Influence of maxillary constriction on nasal resistance and sleep apnea severity in patients with Marfan's syndrome.

BACKGROUND: Marfan's syndrome is associated with a high prevalence of obstructive sleep apnea (OSA). As this syndrome is associated with a characteristic constricted maxilla and high-arched palate, we reasoned that nasal airway constriction and resultant high nasal airway resistance (NAR) may contribute to the development of OSA. Therefore, the aim of this study was to measure NAR in patients with Marfan's syndrome. In addition, we aimed to examine the influence of maxillary morphology on both NAR and the severity of OSA. METHOD: We measured NAR in 13 consecutive patients with Marfan's syndrome and 13 control subjects. NAR was measured by posterior rhinomanometry, and expressed as the inspiratory resistance at a flow of 0.5 L/s. Dental impressions were taken to evaluate maxillary arch morphology, allowing measurement of the following distances: intercuspid (ICD), interpremolar (IPD), intermolar (IMD), and maximum hard palate height (MPH). Ten of the patients and four of the control subjects had previously undergone nocturnal polysomnography. RESULTS: Mean NAR for the Marfan group was more than twice that in the control group (7.7 +/- 1.2 vs 2.9 +/- 0.4 cm H2O/L/s; p < 0.005). The patients also had marked constriction of the maxillary arch compared with control subjects. Two of the lateral maxillary measurements were significantly inversely correlated with NAR. There were significant correlations between various maxillary arch measurements (MPH/ICD, MPH/IPD, MPH/IMD) and the apnea/hypopnea index. CONCLUSION: These data suggest that high NAR is a common feature of Marfan's syndrome. Maxillary constriction with a relatively high hard palate appears to be a major reason for the high NAR. The significant correlations between indexes of maxillary constriction and sleep apnea severity suggest that maxillary morphology may play an important role in the pathophysiology of OSA in Marfan's syndrome.

1,5-Anhydro-beta-L-arabinofuranose from pyrolysis of plant cell wall materials (biomass).

Three types of agricultural waste material having a significant content of L-arabinose have been subjected to mild, vacuum pyrolysis, and yields of 1,5-anhydro-L-arabinofuranose (1) determined. In corn bran, approximately 40% of the L-arabinose is converted into 1, and this conversion is increased to 78% when the bran is subjected to prior acid washing. The inner and outer barks of ponderosa pine give approximately 30% conversion of their L-arabinose content into 1, but orange peel gives only 9% conversion. A mechanism is postulated involving pyrolytic scission of pendant L-arabinofuranose units from polysaccharides, with cyclization to produce 1.

Stereoselective thermal transfer of fructose from sucrose to cyclodextrins.

Branched cyclodextrins (CDs) have been formed by the thermal transfer of a fructosyl group from sucrose to O-6 of one of the glucose residues of cyclomaltohexa- and hepta-ose (alpha-CD and beta-CD). In each case the fructosyl group adds almost entirely in the beta configuration. The resultant fructosylcyclodextrins (Fru-CDs) show increased solubility in water and, in the case of Fru-beta-CD increased ability to solubilize sparingly soluble compounds by inclusion, relative to the parent cyclodextrins. However, the Fru-CDs have similar abilities to form complexes as their respective parent CDs. Fru-CDs act as inhibitors of invertase.

Modes of action of intracellular dextranase and three oligoglucanases from Pseudomonas UQM733.

The action patterns have been studied of a purified, intracellular dextranase and three intracellular alpha-D-glucosidases from Pseudomonas UQM733 on pure isomalto-oligosaccharides. The glucosidases have optimal activity on isomaltotetraose and are therefore classified as oligoglucanases. They have been used to determine the structure of two branched isomalto-oligosaccharides obtained by enzymic degradation of dextran.

Di-D-fructose dianhydrides and related oligomers from thermal treatments of inulin and sucrose.

Thermal treatment of anhydrous, acidified sucrose or inulin yields caramels containing monosaccharides and oligomers, predominantly dianhydrides and higher oligomers derived by the addition of glycosyl residues to dianhydrides. Fourteen dianhydrides, most of which comprise two fructose moieties, have been identified by mass spectroscopy of the per-O-trimethylsilyl ethers. Thirteen of these dianhydrides have been isolated and characterized; five of the dianhydrides are novel compounds and one of these is a glucose-fructose dianhydride. The dianhydrides and related oligomers are thought to have a prebiotic effect by stimulating the proliferation of bifidobacteria in the large intestine.

Purification of intracellular dextranases and D-glucosidases from pseudomonas UQM 733.

The intracellular enzymes of Pseudomonas UQM 733 which act on dextran have been re-investigated mainly by isoelectric focusing. At least three dextranases are present, and one of them (D4) has been purified and shown to be very similar to one of the extracellular endo-dextranases (D1), Three different alpha-D-glucosidases have also been purified.

Fructose-grafted amylose and amylopectin.

Amylose and amylopectin have been heated with sucrose in acidic methyl sulfoxide. The fructose oxocarbonium ion derived from sucrose was transferred as fructofuranosyl groups to 0-6 of the glucans, giving fructoglucans containing up to 7.9% (amylose) and 5.8% (amylopectin) of fructose. The fructosyl units on amylose prevented retrogradation from aqueous solution, resulted in a less-blue iodine complex, and decreased the extent of degradation by amyloglucosidase. The addition of fructosyl units to amylopectin reduced the extent of its degradation by beta-amylase.

Formation of trisaccharides (kestoses) by pyrolysis of sucrose.

Amorphous sucrose, containing citric acid as catalyst, undergoes thermolysis at 100 degrees to yield fructofuranosyl cation and D-glucose. The cation reacts with unchanged sucrose to form all three of the known kestoses, and also their alpha-fructofuranosyl anomers. Two of the latter are resistant to invertase hydrolysis. A new fructosylglucose disaccharide is also formed.

Anhydro sugars and oligosaccharides from the thermolysis of sucrose.

Thermolysis of anhydrous, amorphous, acidified sucrose results in polymerization initially involving the fructosyl cation and later the glucosyl cation. Monomeric and dimeric anhydro sugars form during the thermolysis and are incorporated into the fructoglucan polymer.

Purification, properties, and mode of action of hemicellulase I produced by Ceratocystis paradoxa.

A culture isolate (CP2) of the fungal plant pathogen Ceratocystis paradoxa produces at least five extra-cellular hemicellulases when grown on a medium containing a commercial hemicellulose as inducer. One of the five enzymes, hemicellulase I (HC-I), was purified by ammonium sulphate preceipitation, ion-exchange chromatography (DEAE-Sephadex and then Cellex-CM), and iso-electric focusing at pH 3-10 and 8-10. HC-I behaves as a single protein on a electrophoresis at pH 6.0 and 8.4. The enzyme degrades hemicellulose B (an arabino-4-O-methylglucurono-xylan) and arabinoxylanto arabinose, xylose, xylobiose (Xyl2; beta-D-Xylp-(1 leads to 4)-D-Xyl), and a mixture of arabinose-xylose and xylose oligosaccharides (AraXyln and Xyln, where n=3, 4, or 5). The enzyme is deduced to be an endo-enzyme. Xylotetraose (Xyl4) was the lowest homologue of the xylose oligosaccharides attacked, yielding xylobiose and xylotriose (Xyl3) only. A mechanism is postulated for this reaction. AraXyl5 were slowly hydrolysed to arabinose and the respective xylose saccharide (Xyl2-Xyl5), and thence to Xyl2 and Xyl3. Hydrolysis of the arabinofuranosyl linkage probably does not occur at the same active site as for the xylose oligosaccharides. Hemicellulose B fractions from different sources appeared to be degraded by HC-I. The enzyme showed optimum activity at pH 5.5 and 40 degrees, and Km was 4.24 mg of hemicellulose/ml.

Pyrolysis of inulin, glucose, and fructose.

The pyrolytic behavior of inulin, a (2-->1)-linked fructofuranan, is described. Parallel investigations of the pyrolysis of glucose and of fructose were conducted to supplement the inulin results and to aid comparison with previous results from glucans. Effects of neutral and basic additives are emphasized. As with glucans, the addition of such additives (especially basic) increases the yields of the one-, two-, and three-carbon products (as well as of hexosaccharinolactones), while generally decreasing the yields of anhydro sugar and furan derivatives. The former products include glycolaldehyde, acetol, dihydroxy-acetone, acetic acid, formic acid, and lactic acid. Mechanistic speculations are made regarding the origins of these compounds, as well as of furan derivatives and saccharinic acid lactones. Parallels with alkaline degradation are considered.

Production and purification of two hemicellulases from Cephalosporium sacchari.

The production of extracellular hemicellulases by the fungus Cephalosporium sacchari was studied in the presence of various sources of carbon and at various initial pH values and temperatures. Hemicellulose B and holocellulose from spear grass (Heteropogon contortus) were the best sources of carbon, and the optimum temperature was 27 degrees. The initial pH value had little influence on the final yield of hemicellulases. Two hemicellulases (HC-III and HC-IV) were purified by ammonium sulphate precipitation and isoelectric focusing. Their molecular weights were 10,700 and 9,550, and their pI values 9.40 and 6.0, respectively. HC-III hydrolysed hemicellulose B to oligosaccharides without production of monosaccharides.

Presence of soluble lignin-carbohydrate complexes in the bovine rumen.

The cell-free rumen liquor of a steer on a diet of spear grass has been shown to contain macromolecular substances in which carbohydrates and lignin-derived compounds are covalently bound to each other. The lignin-carbohydrate complexes are soluble at pH 7 or higher, but precipitate at pH 3. At the latter pH, small amounts of a polymer, assumed to be glycoprotein, remain in solution. Some of the lignin-carbohydrate linkages are broken by treatment with alkali. Treatment with 50mM sulphuric acid for a few minutes at room temperature converts part of the complex into an acetone-soluble product, which still contains both carbohydrate and lignin-derived compounds. The formation of soluble lignin-carbohydrate complexes by the action of rumen micro-organisms on the grass may account for the dissolution (and hence the apparent digestion) of about half of the total lignin-intake.

Structures of the oligosaccharides from the enzymic hydrolysis of hemicellulose by a hemicellulase of Ceratocystis paradoxa.

And endo-hemicellulase (HC-II) of Ceratocystis paradoxa degraded spear-grass hemicellulose B to a series of mixed oligosaccharides. Four neutral oligosaccharides (AraXyl2, AraXyl3, Xyl2, and Xyl3), isolated by preparative paper chromatography, were shown by enzymic and methylation techniques to constitute a series of beta-(1 leats to 4)-D-xylose and O-alpha-L-arabinofuranosyl-(1 leads to 3)-O-beta-D-xylopyranosyl-(1 leads to 4)-O-beta-D-xylopyranosyl-(1 leads to 4)-D-xylose, respectively, the latter being a new compound.

Thermal polymerization of some glucofuranose derivatives.

Methyl alpha,beta-D-glucofuranoside (1) and 1,2-O-isopropylidene-alpha-D-glucofuranose (2) have been polymerized thermally, using 0.1% phosphoric acid as catalyst. The resulting alcohol-insoluble polymers were analyzed by gel-permeation chromatography and methylation analysis. The two starting materials gave polymers that were very similar in molecular-weight distribution and in glycosyl-linkage composition. The proportion of furanosyl residues in the polymer, estimated by the relative proportions of furanosyl and pyranosyl residues that could be determined unequivocally by methylation analysis, was approximately 35-40%; higher than is found when glucopyranosides are polymerized, but indicating that significant furanose-pyranose isomerization had occurred during the polymerization process.

Mechanism of formation of 5-(hydroxymethyl)-2-furaldehyde from D-fructose an sucrose.

The literature contains two alternative hypotheses for the mechanism of dehydration of fructose to 5-(hydroxymethyl)-2-furaldehyde (HMF), namely (1) a sequence of reactions commencing with and retaining the fructofuranose ring intact, and (2) a succession of reactions proceeding mainly via open-chain intermediates. The existing evidence for hypotheses (1) and (2) is reviewed and found to favor (1). The major products from fructose in water at 250 degrees, (with and without acid catalysis) have been investigated on a time-resolved basis and analysis of the results was found to confirm the first hypothesis. A necessary fructofuranosyl-cation intermediate in this hypothesis is produced directly by the hydrolysis of sucrose, and reacts to produce HMF in high yields.

Di-D-fructose dianhydrides from the pyrolysis of inulin.

Inulin was pyrolyzed in air to produce di-D-fructose dianhydrides (DFDAs) in approximately 26% yield, three of which were identified by MS, NMR, and comparison with literature data. The mass spectra of the per-O-trimethylsilyl derivatives of the DFDAs are discussed. A mechanism is proposed for the formation of DFDAs from inulin during pyrolysis.

Growth performance and intestinal microbial populations of growing pigs fed diets containing sucrose thermal oligosaccharide caramel.

Four experiments were conducted to determine growth performance and changes in intestinal microbial populations of growing pigs fed diets containing sucrose thermal oligosaccharide caramel (STOC). Ninety-six barrows and 96 gilts were group-fed experimental nursery diets for 32 d after weaning in both Exp. 1 and 2. For each experiment, pigs were divided into four groups of 48 pigs and were fed either control, antibiotic (Apramycin sulfate, 34 mg/kg), 1% STOC, or 2% STOC diets for 32 d after weaning. Each diet was replicated six times with eight pigs per replication. Pigs were either orally gavaged (Exp 1) with water of STOC (2 g per pig) or pigs were creep-fed (Exp 2) either a control diet or a 2% STOC diet for 5 d before weaning (33 d). At the end of Exp 1 and 2, cecal material was collected for enumeration of total aerobes, total anaerobes, coliforms, lactobacilli, and bifidobacteria. Gilts (96 per experiment) used in Exp. 3 and 4 were weaned at 26 d and fed experimental nursery diets for 32 d. They were fed either a control or 1% STOC diet and were otherwise treated as previously described. There were no significant effects of STOC or antibiotic on ADG, ADFI, feed efficiency, or cecal microbial populations in pigs in this study. Feeding diets containing either antibiotic of STOC did not improve animal performance or change intestinal bacterial populations in the present study.

Effect of sucrose thermal oligosaccharide caramel, dietary vitamin-mineral level, and brooding temperature on growth and intestinal bacterial populations of broiler chickens.

Two experiments were conducted to determine the effect of sucrose thermal oligosaccharide caramel (STOC) and dietary vitamin-mineral (V/M) level on growth performance and intestinal microflora of broiler chickens. In Experiment 1, Peterson x Arbor Acres male broilers (n = 384) were randomly allocated into four groups that were fed either the control diet or diets containing the antibiotic virginiamycin (11 mg/kg), 3.7% STOC or 7.5% STOC for 4 wk at brooding temperatures of 32 to 29.7 C. Weight gains for broilers in Experiment 1 were greater (P < 0.001) for birds fed STOC diets, with weight gains of 763, 822, 1,124, and 1,080 g for birds on the control, antibiotic, 3.7% STOC, and 7.5% STOC diets, respectively. Feed intake and feed conversion by birds fed STOC diets were also significantly improved. Cecal bifidobacterial numbers were increased (P < 0.03) over the control diet with numbers being 5.98, 6.99, 7.47, and 7.39 log10 cfu/g cecal DM, respectively. In Experiment 2, Peterson x Hubbard male broilers (n = 384) were used in a 2 x 2 x 2 factorial arrangement with two levels of V/M premix (0.5 or 1% of the diet), two levels of STOC (0 or 3.5% of the diet), and two brooding temperatures, normal (32 to 23.6 C) or high (32 to 29.7 C) for 4 wk. Feeding the STOC diet improved (P < 0.05) weight gain, feed intake, and feed conversion of broilers. The effect of STOC on animal performance was less evident when broilers were fed twice the NRC recommended levels of V/M. Feeding the STOC diets resulted in a significantly greater increase in weight gain at high brooding temperatures than at normal brooding temperatures. There was also a reduction (P < 0.05) in numbers of total aerobes and coliforms in the ceca of birds fed diets containing STOC. Feeding STOC has potential to improve growth performance of broiler chickens.