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PubMed2006

Morphology of protein particles produced by spray freezing of concentrated solutions.

The mechanisms for the formation of high surface area lysozyme particles in spray freezing processes are described as a function of spray geometry and atomization, solute concentration and the calculated cooling rate. In the spray freeze-drying (SFD) process, droplets are atomized into a gas and then freeze upon contact with a liquid cryogen. In the spray freezing into liquid (SFL) process, a solution is sprayed directly into the liquid cryogen below the gas-liquid meniscus. A wide range of feed concentrations is examined for two cryogens, liquid nitrogen (LN2) and isopentane (i-C5). The particle morphologies are characterized by SEM micrographs and BET measurements of specific surface area. As a result of boiling of the cryogen (Leidenfrost effect), the cooling rate for SFL into LN2 is several orders of magnitude slower than for SFL into i-C5 and for SFD in the case of either LN2 or i-C5. For 50 mg/mL concentrated feed solutions, the slower cooling of SFL into LN2 leads to a surface area of 34 m(2)/g. For the other three cases with more rapid cooling rates, surface areas were greater than 100 m(2)/g. The ability to adjust the cooling rate to vary the final particle surface area is beneficial for designing particles for controlled release applications.

Algorithms↗
PubMed2002

Airborne dust and allergen generation during dusting with and without spray polish.

BACKGROUND: Dusting is a commonly used method for dust removal from surfaces in the home. However, the process of dusting may contribute to airborne dust levels by disturbing dust particles from a surface and failing to remove it from the indoor environment. OBJECTIVE: We sought to measure the quantity of allergen-laden dust disturbed into the air during dusting and discover whether applying spray polish to either the dusty surface or the cleaning cloth reduced this amount. METHODS: A common furniture polish was tested for its ability to prevent dust particles and major house dust mite (Der p 1) or major cat (Fel d 1) allergen from becoming airborne during dusting. Tests were completed with a repeatable mechanized dusting procedure with polish sprayed onto either a cleaning cloth or directly onto a surface, and this was compared with a control procedure with a standard duster. Airborne dust was measured with an air-particle counter and by means of anti-Der p 1 or anti-Fel d 1 ELISA. RESULTS: Considerable quantities of dust became airborne during dusting. When polish was sprayed onto the cleaning cloth, the concentration of airborne dust particles was reduced by a mean of 83.4%, house dust mite allergen by 50.3%, and cat allergen by 57.4% when compared with dry-cloth controls. Spraying polish directly onto the surface was even more effective at reducing the generation of airborne particles (92.9%) and allergens (Der p 1 by > or =95% to below the sensitivity of the ELISA and Fel d 1 by 95%). All reductions were significant when compared with dry-cloth controls (P <.01, Mann-Whitney U test). CONCLUSIONS: This study showed that application of a polish spray to either the surface or the cloth during dusting greatly reduced dust and allergen evolution into the air, which should reduce exposure to airborne allergens in the home.

Air↗
PubMed1989

Cryotechniques in macromolecular research (a comparative study).

There is no single method which would provide an unambiguous image of all types of biological macromolecules. The choice of method depends largely on the size and properties of the macromolecule. Obviously small molecules are best visualized by negative staining, the problems appear with negative staining of larger structures. Here, the uncertainty about which part of the complex is actually stained (top or bottom) makes correct interpretation difficult. Shadowing techniques have the advantage of both visualizing the surface and also delineating the whole macromolecule, but suffer from lower resolution due to the graininess of the metal. However, they are superior to negative staining for the visualization of thin linear macromolecules. The next series of problems includes the interaction of macromolecules with supporting films, glass coverslips or mica, which can be hydrophobic, hydrophilic or charged and these properties can influence the orientation of the molecules. Surface tension forces during air-drying must also be considered. We have used a variety of preparative techniques in our studies of biological macromolecules: (a) negative staining; (b) air-drying from ethanol; (c) glycerol-spraying; (d) adsorption freeze-drying; (e) monolayer freeze-etching. These methods have been tested on small viruses, water soluble proteins (ribosomes, F-actin, microtubules) and transmembrane proteins requiring the presence of detergents (sarcoplasmic reticulum ATPase, fibronectin receptor). We find that freeze-drying is the most reliable and easy method for molecules that withstand distilled water; freeze-etching can be successfully applied to transmembrane proteins (even in the presence of detergents or salt); the glycerol-spray technique provides an excellent alternative to the cryotechniques in particular for studies of single linear molecules.

Adenoviridae↗
PubMed1997

Studies on the response of nitroglycerin oral spray compared with sublingual tablets for angina pectoris patients with dry mouth. A multicenter trial.

Nitroglycerin (glyceryl trinitrate, CAS 55-63-0, NTG) administered with an oral spray may be more effective in relieving anginal pain than sublingual tablets especially when the patient's mouth is dry. In this study, the effect of a NTG oral spray (Myocor Spray) on exercise-induced angina was compared with that of a sublingual tablet in relation to the oral dryness. In 17 patients with effort angina, graded bicycle exercise was performed twice at an interval of one week. Exercise was discontinued upon the onset of moderate anginal pain. Immediately after exercise, the oral dryness was evaluated by touching the tip of the tongue with a blotting paper for a moment. Then, 0.3 mg of NTG was administered by either a squirt of spray or a sublingual tablet in a randomized crossover fashion. Exercise results were reproducible between two exercise tests. According to the extent of the wet area of the blotting paper, the subjects were divided into two groups. In 7 patients of the wet group, the remission times of chest pain and ST segment depression were not significantly different by the formulation of NTG. In 10 patients of the dry group, however, both chest pain and ST depression more rapidly recovered with use of the oral spray (p < 0.05 and p < 0.05, respectively). These results strongly suggest that the NTG oral spray is superior to the sublingual tablet in relieving anginal attacks, when the oral wetness is decreased.

Administration, Sublingual↗
PubMed1976

A comparison of the ultrastructure of spray-frozen and freeze-etched or freeze-dried bull and boar spermatozoa with that after chemical fixation.

The ultrastructure of bull and boar spermatozoa was investigated following different cryopreparation methods and chemical fixation. Spray-freezing was used for cryofixation in both freeze-etching and freeze-drying studies. Freeze-etching of boar spermatozoa revealed that the arrangement of the postnuclear striations differed from that in the bull. Freeze-drying gave excellent results for structural preservation, which were equal to those of chemical fixation. Some structural details not visible in chemically fixed cells were detected in freeze-dried and vacuum-embedded bull and boar spermatozoa, e.g. the arrangement of the lamellar nuclear contents, known from freeze-fractures, and a fine lamellar structure of the acrosomal contents. Cryofixation by spray-freezing combined with freeze-drying makes any contact of the cells with fixatives, buffer solutions and dehydration media unnecessary, and potentially provides all the advantages of ultrathin sectioning required for histochemical studies.

Acrosome↗
PubMed2006

The stability of insulin in solid formulations containing melezitose and starch. Effects of processing and excipients.

Solid insulin formulations obtained by different methods of preparation were compared with respect to chemical stability and morphology. Spray- and freeze-drying, solution enhanced dispersion by supercritical fluids (SEDS) and precipitation into starch microspheres were the methods used for preparation of solid powders. The excipients applied were melezitose, starch, and sodium taurocholate. The stability of the samples was evaluated after storage in open containers at 25 degrees C and 30% RH for 6 months. All samples were amorphous after processing and storage as detected by XRD, except for the starch microspheres which were semi-crystalline. The spray- and freeze-dried samples containing melezitose and sodium taurocholate experienced a significant water uptake during storage, resulting in changes in morphology and disappearance of Tg. However, the chemical stability of these samples did not seem to be affected by the water uptake. Changes in morphology were not observed for the SEDS powders and the starch microspheres. The chemical stability of the samples was assessed by HPLC. In general, conventional spray- and freeze drying resulted in samples with higher chemical stability compared to SEDS powders and starch microspheres. Nevertheless, the excipients applied were observed to be of major importance, and further optimization of the formulation as well as processing conditions may lead to slightly different conclusions.

Calorimetry, Differential Scanning↗
PubMed1985

Influence of protein intake on per os zinc deficiency treatment in sheep.

Two experiments were conducted on 20 male 3.5 month-old Limousin X Romanoff lambs, weighing between 30 and 35 kg. They received a zinc deficient diet based on 50% late harvested hay and 50% barley straw containing from 8 mg Zn/kg dry matter to 11.7 mg Zn/kg dry matter and sprayed with caramel. Sheep were hypozincaemic from the 14th or 21st day. In the first experiment, the zinc level of the diet (94 g crude protein/kg DM from urea) was increased to 50 mg Zn/kg dry matter on the 35th day. At the same time, half the animals received egg albumin instead of urea; both diets were isoproteic. No change in zincaemia was observed in either of the two groups: it remained low. On day 51, the albumin group received an increase in dietary protein by the addition of more egg albumin, so that the diet contained up to 148 g crude protein/kg dry matter, the usual requirements of growing lambs. The zincaemia of these sheep started to increase and was restored to normal with a diet that contained 150 mg Zn/kg dry matter. The zincaemia of the low protein group remained unchanged whatever the zinc level. In the second experiment, increasing the zinc level with the diet (70 g crude protein from egg albumin) from 11.6 to 300 mg/kg dry matter restored the zincaemia either in the high protein group (140 g crude protein/kg dry matter) or in the low protein group (70 g crude protein/kg dry matter).(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed2003

Effect of method of application of a fibrolytic enzyme product on digestive processes and milk production in Holstein-Friesian cows.

Four multiparous cows with cannulas in the rumen and proximal duodenum were used in early lactation in a 4 x 4 Latin square experiment to investigate the effect of method of application of a fibrolytic enzyme product on digestive processes and milk production. The cows were given ad libitum a total mixed ration (TMR) composed of 57% (dry matter basis) forage (3:1 corn silage:grass silage) and 43% concentrates. The TMR contained (g/kg dry matter): 274 neutral detergent fiber, 295 starch, 180 crude protein. Treatments were TMR alone or TMR with the enzyme product added (2 kg/1000 kg TMR dry matter) either sprayed on the TMR 1 h before the morning feed (TMR-E), sprayed only on the concentrate the day before feeding (Concs-E), or infused into the rumen for 14 h/d (Rumen-E). There was no significant effect on either feed intake or milk yield but both were highest on TMR-E. Rumen digestibility of dry matter, organic matter, and starch was unaffected by the enzyme. Digestibility of NDF was lowest on TMR-E in the rumen but highest postruminally. Total tract digestibility was highest on TMR-E for dry matter, organic matter, and starch but treatment differences were nonsignificant for neutral detergent fiber. Corn silage stover retention time in the rumen was reduced by all enzyme treatments but postruminal transit time was increased so the decline in total tract retention time with enzymes was not significant. It is suggested that the tendency for enzymes to reduce particle retention time in the rumen may, by reducing the time available for fibrolysis to occur, at least partly explain the variability in the reported responses to enzyme treatment.

Acetic Acid↗
PubMed1999

Octylcyanoacrylate for the treatment of partial-thickness burns in swine: a randomized, controlled experiment.

OBJECTIVE: To compare re-epithelialization rates of superficial partial-thickness burns treated with octylcyanoacrylate (OCA), silver sulfadiazine (SSD), and dry gauze (controls) in swine. METHODS: This was a prospective, longitudinal, blinded, controlled, experimental trial using anesthetized swine. Sixty-three standardized burns were created by applying an aluminum bar preheated to 80 degrees C for 20 seconds to the flanks of four young pigs. Three equal sets of 21 burns were randomly treated with OCA spray, SSD, or dry gauze (controls). Full-thickness biopsies were taken after 30 minutes and at seven and 14 days for blinded histopathologic evaluation by two dermatopathologists using hematoxylin and eosin staining. The percent of wound re-epithelialization was measured at days 7 and 14, calculated by dividing the length of the regenerated epidermis by the measured width of the biopsy. Analysis of variance (ANOVA) and repeated-measures ANOVA controlling for the individual pig were used for comparisons among groups. This study had 80% power to demonstrate a large between-group difference in percent re-epithelization (alpha = 0.05). RESULTS: There were 63 burns and 126 biopsies. Ten biopsies were excluded for technical reasons. At seven days, there was a significant between-group difference in percent re-epithelialization. Percent re-epithelialization was greatest in the OCA group (65.0%), followed by the SSD group (37.6%), and lowest in the control group (8.8%). At 14 days, all wounds demonstrated near complete re-epithelialization and there was no significant difference in the percent of re-epithelialization among the groups. There was only one wound infection in the OCA group. CONCLUSIONS: Under these study conditions, treatment of partial-thickness burns with OCA spray resulted in a higher percent of re-epithelialization at seven but not 14 days when compared with both SSD and control, with no significant increase in infection rates. Future studies should evaluate the use of OCA for the treatment of burns in humans.

Analysis of Variance↗
PubMed2006

Enhanced survival of GroESL-overproducing Lactobacillus paracasei NFBC 338 under stressful conditions induced by drying.

GroESL-overproducing Lactobacillus paracasei NFBC 338 was dried, and its viability was compared with that of controls. Spray- and freeze-dried cultures overproducing GroESL exhibited approximately 10-fold and 2-fold better survival, respectively, demonstrating the importance of GroESL in stress tolerance, which can be exploited to enhance the technological performance of sensitive probiotic cultures.

Bacterial Proteins↗
PubMedDate not supplied

Biological monitoring of organophosphate pesticides in preschool children in an agricultural community in Thailand.

Organophosphate pesticide exposures of preschool children in a Thailand agricultural community and reference children living outside the farm area in the same subdistrict were determined. Levels of dialkylphosphate (DAP) metabolites were measured in first-morning-void urine samples. During the dry season (April-May), the farm children excreted significantly higher levels of all DAP metabolites than the reference children did (Mann-Whitney U test, p < 0.05; Wilcoxon signed-rank text, p < 0.05). During the wet season (September-October), DAP metabolite levels were similar in the two groups. Reference children showed no significant difference related to season. Pesticide spraying during the dry season is a likely cause of the farm children's organophosphate exposures.

Child, Preschool↗
PubMed2001

How wet should dentin be? Comparison of methods to remove excess water during moist bonding.

PURPOSE: The aim of this study was to evaluate the shear bond strength of two adhesive systems when applied on dentin surfaces with different degrees of wetness. MATERIALS AND METHODS: Two-hundred ten dentin specimens were used. After conditioning with 35% phosphoric acid gel and washing, seven methods of drying dentin were used: 30 s air spray (groups 1 and 2), 5 s air spray (groups 3 and 4), dry cotton pellets (groups 7 and 8), wet cotton pellets (groups 9 and 10), microbrush (groups 11 and 12), absorbent paper (groups 13 and 14). The last group was not dried; the dentin surfaces were left overwet (groups 5 and 6). Prime & Bond 2.1 adhesive was applied on the odd-numbered groups and Scotchbond Multi Purpose on the even-numbered groups. Z100 composite cylinders were bonded to the adhesive and the specimens were subjected to a shear bond test. RESULTS: The Least-Squares Means test was used to compare the following results, where different letters indicate significantly different mean values: Group 9 (G9) = 23.2 MPa (a), G3 = 21.3 MPa (ab), G2 = 19.5 MPa (bc), G10 = 18.6 MPa (bc), G14 = 16.3 MPa (cd), G8 = 16.1 MPa (cd), G4 = 14.6 MPa (de), G13 = 14.0 MPa (de), G11 = 13.9 MPa (de), G7 = 13.5 MPa (de), G12 = 12.1 MPa (e), G1 = 8.2 MPa (f), G5 = 2.7 MPa (g), G6 = 2.4 MPa (g). CONCLUSION: The adhesion values were affected both by the degree of dentin wetness and by the adhesive systems.

Acetone↗
PubMed2006

Application of polymeric surfactants in micellar electrokinetic chromatography-electrospray ionization mass spectrometry of benzodiazepines and benzoxazocine chiral drugs.

Chiral micellar EKC (CMEKC) coupled to ESI-MS using polymeric surfactants as pseudostationary phases is investigated for simultaneous enantioseparation of two benzodiazepines, (+/-)-oxazepam ((+/-)-OXA) and (+/-)-lorazepam ((+/-)-LOR), and one benzoxazocine, (+/-)-nefopam ((+/-)-NEF). First, enantioselectivity and electrospray sensitivity of six chiral polymeric surfactants for all three chiral compounds are compared. Second, using poly(sodium N-undecenoyl-L-leucinate) as pseudostationary phase, the organic modifiers (methanol (MeOH), isopropanol, and ACN) are added into the running buffer to further improve chiral resolution (RS). Next, a CMEKC-ESI-MS method for the simultaneous enantioseparation of two benzodiazepines is further developed by using a dipeptide polymeric surfactant, poly(sodium N-undecenoxy carbonyl-L,L-leucyl-valinate) (poly-L,L-SUCLV). The CMEKC conditions including nebulizer pressure, capillary length, ammonium acetate concentration, pH, poly-L,L-SUCLV concentration, and capillary temperature were optimized to achieve maximum chiral RS and highest sensitivity of MS detection. The spray chamber parameters (drying gas temperature and drying gas flow rate) as well as sheath liquid conditions (MeOH content, pH, flow rate, and ionic strength) were found to significantly influence MS S/N of both (+/-)-OXA and (+/-)-LOR. Finally, a comparative study between simultaneous UV and MS detection showed high plate numbers, better chiral RS, and enhanced detectability with CMEKC-MS. However, speed of analysis was faster using CMEKC-UV.

Benzodiazepines↗
PubMed2006

Anthrax vaccine powder formulations for nasal mucosal delivery.

Anthrax remains a serious threat worldwide as a bioterror agent. A second-generation anthrax vaccine currently under clinical evaluation consists of a recombinant Protective Antigen (rPA) of Bacillus anthracis. We have previously demonstrated that complete protection against inhalational anthrax can be achieved in a rabbit model, by intranasal delivery of a powder rPA formulation. Here we describe the preformulation and formulation development of such powder formulations. The physical stability of rPA was studied in solution as a function of pH and temperature using circular dichroism (CD), and UV-visible absorption and fluorescence spectroscopies. Extensive aggregation of rPA was observed at physiological temperatures. An empirical phase diagram, constructed using a combination of CD and fluorescence data, suggests that rPA is most thermally stable within the pH range of 6-8. To identify potential stabilizers, a library of GRAS excipients was screened using an aggregation sensitive turbidity assay, CD, and fluorescence. Based on these stability profiles, spray freeze-dried (SFD) formulations were prepared at pH 7-8 using trehalose as stabilizer and a CpG-containing oligonucleotide adjuvant. SFD formulations displayed substantial improvement in storage stability over liquid formulations. In combination with noninvasive intranasal delivery, such powder formulations may offer an attractive approach for mass biodefense immunization.

Administration, Intranasal↗
PubMed1993

Electron microscopic images suggest both ends of caldesmon interact with actin filaments.

An improved rotary shadowing technique enabled us to visualize chicken gizzard caldesmon (CaD) and its complexes with one or two covalently linked calmodulin (CaM) molecules by electron microscopy. Using a monoclonal antibody against an epitope in the N-terminal region of CaD (anti-N), we can now identify the end of the molecule that is involved in binding to another protein molecule. Thus in the 1:1 complex of CaD and CaM, the CaM molecule was almost always associated with the C-terminus of CaD, indicating preferential CaM-binding to the C-terminal region. We have also studied binding of CaD to filamentous actin (F-actin), using an EM technique that avoids spraying or freeze drying and thereby preserves the structure of F-actin. Only one end of CaD appeared to bind to F-actin, leaving the rest of the molecule projecting away from the filament. While the majority of anti-N bound at the free end of CaD, some antibody molecules were found on F-actin. These findings suggest that either end of CaD can bind to F-actin. Experiments using a monoclonal antibody against the C-terminus of CaD (anti-C) supported this idea. When the native thin filaments that contain endogenous CaD were incubated with anti-N, almost all the bound antibodies were found on the filaments, indicating that the N-terminal regions of CaD interact with actin, and that the binding affinity of the N-terminal region of CaD for actin is higher in vivo than that in vitro, either because the properties of CaD have been altered during purification, or because of the presence of some other component(s) associated with the native filaments.

Actins↗
PubMed1975

Persistence of parathion and its oxidation to paraoxon on the soil surface as related to worker reentry into treated crops.

Soil and dust samples from beneath citrus trees contained relatively high concentrations of paraoxon and parathion for at least 45 days after parathion was applied at normal rates. These data indicate that parathion dripping on dry soil from sprayed crops, or sprayed directly on the soil surface, can persist for long periods and be oxidized to the highly toxic paraoxon. The residue concentrations are much higher on the loose dust particles than in the bulk soil. The data indicate that the soil or grove floor should be considered as a possible contributing source of toxicant along with foliage, or dust on foliage, to workers reentering treated fields. In any event, the data confirmed the high rates of oxidation of parathion to paraoxon on particulate matter, whether on foliage (SPEAR et al., 1974) or at the soil surface. The particulate matter appears to contribute to the accumulation of paraoxon, either by enhancing oxidation of parathion to paraoxon or by decreasing dissipation of paraoxon.

Agricultural Workers' Diseases↗
PubMed2005

New method for testing solar sensitivity of commercial formulations of the granulovirus of codling moth (Cydia pomonella, Tortricidae: Lepidoptera).

A method for screening codling moth granulovirus (CpGV) formulation sensitivity to sunlight using specially prepared half apples and a solar simulator is described. The half apple preparation allows an even coverage of virus over the surface of the fruit that would not be possible using whole apples. Leaves and artificial medium were not usable for extended periods of exposure in the solar simulator due to excess drying. Fruit was sprayed with 10(-3) and 10(-5) dilutions of three commercial formulations of CpGV (Carpovirusine, Cyd-X, and Virosoft) and infested with codling moth neonates. Half of the sprayed fruit was exposed to 650 W/m2 for 4 h in an Atlas Suntest CPS solar simulator resulting in an accumulated radiant energy of 9.36x10(6) J/m2 before they were infested with neonate codling moth larvae. Spraying non-irradiated fruit with the 10(-3) dilution of Cyd-X and Virosoft resulted in nearly 100% mortality of neonate larvae. Irradiation reduced viral activity by 71-98% at the 10(-3) dilution and by up to 32% at the 10(-5) dilution relative to non-irradiated fruit. The procedures utilized enabled good preservation of the fruit throughout the incubation period and minimized invasion of the fruit by plant pathogens and saprophytic organisms. This laboratory method for screening candidate formulations and potential UV protectants could conserve time and resources by eliminating adjuvants with less potential in laboratory tests and field testing only the most promising candidates. It also enables year-round testing.

Aerosols↗