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Numerical and experimental evaluation of energy inputs, temperature gradients, and thermal stresses during restorative procedures.

Wet cutting in enamel should be used during restorative procedures. According to evidence reported here, dry cutting can induce sufficiently high thermal stresses to fracture the enamel. Temperatures resulting from dry cutting in dentin are high enough to cause biologic pulp damage if the cutting is within 1 to 2 mm of the pulp. Cracks induced in the cavity walls by dry cutting may eventually contribute to marginal failure. A hand-held syringe directing a small, high-velocity stream of water into the cutting region is a more effective cooling technique than an air-water spray.

Adult↗

Evaluation of a novel synthetic sealant for inhibition of cardiac adhesions and clinical experience in cardiac surgery procedures.

BACKGROUND: Pericardial adhesions subject patients requiring reoperation to potential injuries to the heart, great vessels, and cardiac grafts during the re-sternotomy. These adhesions can severely complicate re-operations by making re-entry hazardous, impeding orientation and visibility, increasing the amount of blood loss, and prolonging the operation time. The efficacy of an in situ-forming polyethylene glycol (PEG) material, CoSeal surgical sealant (CoSeal), for inhibiting cardiac adhesions in an animal model is reported. It is currently estimated that 10-20% of patients undergoing aortic valve replacement and coronary artery bypass grafting (CABG) will require a second operation later in their lives. Successful clinical experience using CoSeal for sealing suture lines of the aorta and CABGs with the data reported here suggest that CoSeal may have multiple applications in cardiac surgery. METHODS: In rabbits, a sternotomy and pericardiotomy were performed to expose the heart and the epicardium of the left ventricular surface. The epicardium was abraded for five minutes with dry gauze and cotton to develop punctate bleeding. In treated animals, CoSeal(R) or Tissucol(R) was applied directly to the abraded bleeding epicardium while retracting the pericardium. The pericardium was released, and the material over-sprayed to the cut edges of the pericardium. No material was applied in control animals. RESULTS: At necropsy, CoSeal(R) was found to significantly reduce the formation of adhesions, the tenacity of the adhesions, and the percent of the abraded site with adhesions as compared to surgical control and Tissucol. Tissucol showed no significant difference from the surgical control in any adhesion parameter. CoSeal treated hearts showed re-establishment of the mesothelial layer and tissue morphology similar to a normal un-operated heart. During the clinical cardiac procedures, CoSeal was easily mixed and applied to the suture lines of the aorta and coronary artery grafts. No bleeding was found at the suture lines. CONCLUSIONS: In the rabbit cardiac adhesion model, CoSeal significantly reduced the formation of adhesions as compared to surgical control and Tissucol, and demonstrated good biocompatibility. In CoSeal treated patients undergoing cardiopulmonary bypass or vessel repair, sealing was achieved comparable to previous cases using Tissucol fibrin sealant. CoSeal effectively sealed the suture lines of the aorta and coronary artery bypass grafts.

Animals↗

Malaria in Zimbabwe: comparisons of IFAT levels, parasite and spleen rates among high, medium and lower altitude areas and between dry and rainy seasons.

OBJECTIVES: To study the extent of malaria prevalence among children at various elevations above sea level and in children during the dry and rainy seasons in Zimbabwe. DESIGN: Cross sectional. SETTING: Primary and secondary schools. SUBJECTS: The number of children (aged about eight years in Grade Three and 13 years in Form One) examined in November 1992 was 103 in Chitungwiza (above 1,200 m), 94 in Gokwe (900 to 1,200 m) and 96 in Sasame (under 900 m). In April 1993 it was 86 in Chitungwiza, 78 in Gokwe and 81 in Sasame. MAIN OUTCOME MEASURE: Indirect Fluorescent Antibody Test (IFAT) levels, parasite and spleen rates. RESULTS: No splenomegaly was detected in children in schools above 900 m. While no parasitaemia was detected in children in schools above 1200 m, one (0.6%, 95% CI to -0.6 to 1.7) child and 37 (20.9%, 95% CI 14.9 to 26.9) children in schools between 900 and 1,200 m and below 900 m, respectively, had parasitaemia. The IFAT levels were lowest in children in areas above 1,200 m and increased significantly with decreasing altitude (x2 for linear trend 332, p < 0.001). The parasite rate in the rainy season (39.5%, 95% CI 28.9 to 50.2) was significantly (p < 0.001) higher than that in the dry season (5.2%, 95% CI 0.8 to 9.7). No significant differences in the IFAT levels (p = 0.208) and in the spleen rates (p = 0.180) were observed between the dry and rainy seasons. Sixty five percent of all children in schools above 1,200 m visiting rural areas used no protective measures against malaria. All children in schools under 900 m reported that their homes were sprayed, but very few other prophylactic measures (seven children used antimalarial drugs and 15 children used a net) were reported. CONCLUSIONS: Malaria acquisition is uncommon above 900 m and the people in these areas are highly vulnerable to malaria.

Adolescent↗

Microencapsulation of drugs with aqueous colloidal polymer dispersions.

Sustained-release polymer particles containing drugs with various solubility characteristics (ibuprofen, theophylline, guaifenesin, and pseudoephedrine HCl) were prepared with colloidal polymer dispersions in a completely aqueous environment as an alternative to conventional microencapsulation techniques, which use organic solvents. Spherical particles were prepared by spraying or dropping dilute sodium alginate solutions (0.67%, w/w) containing the dissolved or dispersed drug and colloidal polymer particles into calcium chloride solutions. The gelled particles, which formed by ionotropic gelation of the polysaccharide with calcium ions, were dried and cured at 60 degrees C to cause fusion of the colloidal polymer particles into a homogeneous matrix system. Actual drug contents close to 50% and encapsulation efficiencies of between 80 and 98% were achieved with all drugs. Guaifenesin and ibuprofen acted as plasticizers for the ethyl cellulose pseudolatex, whereas with theophylline and pseudoephedrine HCl, dibutyl sebacate had to be added as a plasticizer to yield a nondisintegrating polymer matrix. The stirring time before separation of the particles from the gelation medium had to be minimized with the water-soluble drugs to maximize drug loading; however, it was not critical with the water-insoluble drugs. Drug release was a function of the solubility of the drug, drug loading, and the type of polymer dispersion used.

Capsules↗

Bone grafting and guided bone regeneration for immediate dental implants in humans.

This study evaluated bone regeneration and osseointegration of hydroxyapatite (HA) coated and titanium plasma sprayed (TPS) implants placed in sockets immediately after extraction in 36 adults, mean age 55.2 years (range 26 to 81 years). Twelve TPS and 10 HA-coated implants in 20 patients were grafted with demineralized freeze-dried bone allograft (DFDBA), covered with a barrier material, and the facial flap coronally positioned to attain primary closure (experimental). The remaining 11 TPS and 10 HA-coated implants were placed similarly, except that no DFDBA was used (control). Osseous structures were measured at the initial placement and 6-month re-entry surgeries. At the 6-month re-entry, all implants placed were clinically osseointegrated. Bone resorption at the most coronal socket crest was -1.53 mm for the grafted group and -1.59 mm for the control group. Crestal bone apposition of 1.39 mm was noted at the most apical socket crest (ASC) for the grafted group, whereas crestal resorption of -0.11 mm was noted in the ungrafted control group (P < 0.02). Bone fill from the base of the deepest osseous defect was 5.68 mm for the grafted group and 3.18 mm for the control group (P < 0.04). Complete resolution of osseous defects occurred at 15 of 22 sites in the grafted group and at 9 of 21 sites in the control group. Clinical exposure of the barrier material and a subsequent inflammatory response at 27 of 43 sites, requires removal of the material prior to the 6-month re-entry and was associated with significantly more bone loss at the ASC sites (P < 0.01). There was no significant difference for any of the parameters when comparing the TPS with the HA-coated implants.

Adult↗

Rationale for using Peltophorum africanum (Fabaceae) extracts in veterinary medicine.

Peltophorum africanum (Fabaceae) is a deciduous tree widespread in southern Africa. The plant has many ethnomedical and ethnoveterinary uses. Root and bark decoctions are used to treat diarrhoea, dysentery, sore throat, wounds, back and joint pains, HIV-AIDS, venereal diseases and infertility. Pastoralists and rural farmers use the root and bark extracts to treat diarrhoea, dysentery, infertility, and to promote well-being and resistance to diseases in cattle. To evaluate these ethnobotanical leads, dried leaves, stem bark and root bark were extracted with ethanol, acetone, dichloromethane and hexane. Polyphenols in the extract were determined by the Folin-Ciocalteu method with gallic acid as standard. Qualitative antioxidant activity was screened by spraying thin layer chromatograms (TLC) of the extracts with 0.2% 1,1-diphenyl-2-picryl hydrazyl (DPPH), and quantified with Trolox equivalent antioxidant capacity (TEAC) assay. Minimum inhibitory concentration (MIC) and total antibacterial activity (TAA) were determined by serial microplate dilution for Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Enterococcus faecalis, with gentamicin as standard and tetrazolium violet as growth indicator. Acetone and ethanol extracted the largest quantity of material. Polyphenols concentration was 49.2% in acetone extract of the root and 3.8% in dichloromethane extract of the leaf. Antioxidant activity of at least 5 antioxidant compounds as measured by TEAC ranged from 1.34 (ethanol extract of the root) to 0.01 (hexane extract of the leaf). The total antibacterial activity (volume to which active compounds present in 1 g plant material can be diluted and still inhibit bacterial growth) was 1263 ml/g for ethanol extract of the root against S. aureus, and 800 ml/g for acetone extract of the root against P. aeruginosa. There was substantial activity against both Gram-positive and Gram-negative bacteria, with MIC values of 0.08 mg/ml for S. aureus and 0.16 mg/ml for P. aeruginosa. There is therefore a rationale for the traditional use of root and bark of P. africanum in treating bacterial infection related diseases.

Animals↗

Effect of opacifiers on color stability of pigmented maxillofacial silicone A-2186 subjected to artificial aging.

PURPOSE: This study was designed to determine the effect of opacifiers used at different ratios on the color stability of pigmented A-2186 silicone maxillofacial elastomers and to evaluate the color spectrophotometrically before and after artificial aging. MATERIALS AND METHODS: Sixty experimental groups of elastomers were made using various concentrations (5%, 10%, and 15%) of 4 opacifiers (Georgia kaolin powder neutral, kaolin powder calcined, Artskin white, and dry pigment titanium white) with 1 of 5 dry earth cosmetic pigment groups (no pigment [control], red, yellow ochre, burnt sienna, and a mixture of all pigments). Five specimens of each elastomer were tested, for a total of 300 specimens. All specimens were placed in an aging chamber and artificially aged by exposure to light, water spray, fluctuating temperatures, and humidity. CIE L*a*b* values were measured by spectrophotometer. The color differences (Delta E*) at various exposure energies (150, 300, and 450 kJ/m(2)) were subjected to 4-way analysis of variance with repeated measures (super ANOVA). Mean values were compared with Tukey-Kramer intervals calculated at the 0.05 significance level. RESULTS: The trained human eye can detect color changes (Delta E*) greater than 1.0. Adding all pigments to any of the kaolin groups did not protect silicone A-2186 from color degradation over time. Mixing red pigment in all groups at all times drastically increased DeltaE* values ranging from 0.1 to 1.3 up to 16.6 to 49.6. Yellow ochre had an effect only with 10% and 15% concentrations of kaolin powder calcined, increasing the value of Delta E* to greater than 1.0. Burnt sienna had an effect only with a 15% concentration of kaolin powder calcined, increasing the value of Delta E* at 300 and 450 kJ/m(2) to greater than 11.0. At the 5% concentration, kaolin powder calcined had the smallest color changes, followed by, in order, dry pigment titanium white, Artskin white, and Georgia kaolin. At the 10% concentration, Artskin white had the smallest color changes, followed by, in order, dry pigment titanium white, kaolin powder calcined, and Georgia kaolin. At the 15% concentration, Artskin white again had the smallest color changes, followed by, in order, dry pigment titanium white, Georgia kaolin, and the kaolin powder calcined. The smallest color changes in each kaolin group were at the 10% concentration for Artskin white, dry pigment titanium white, and kaolin powder calcined and at the 5% concentration for Georgia kaolin. CONCLUSIONS: Mixing dry earth cosmetic pigments with opacifiers did not protect silicone A-2186 from color degradation over time, especially in the case of red pigment. The group in which pigments were mixed with 10% Artskin white had the smallest color changes over time, followed by, in order, the groups in which pigments were mixed with 10% dry pigment titanium white, 10% kaolin powder calcined, and 5% Georgia kaolin. Red pigment had a significant effect on all opacifiers, especially Georgia kaolin and kaolin powder calcined. Yellow ochre and burnt sienna had an effect only on 15% kaolin powder calcined. Among all the pigment groups tested, yellow ochre remained the most color stable over time.

Analysis of Variance↗

Transformation and segregation of GFP fluorescence and glyphosate resistance in horseweed (Conyza canadensis) hybrids.

The goal of this research was to generate a breeding population of horseweed segregating for glyphosate resistance. In order to generate a marker to select between hybrids of glyphosate resistant (GR) and glyphosate susceptible (GS) horseweed, a GR horseweed accession from western Tennessee was transformed with a green fluorescent protein (GFP) transgene. The GFP marker allowed for the simple and accurate determination of GR hybrid plants by visual observation. GR plants were shown to be transgenic via the green fluorescence under UV light, and resistant to glyphosate when sprayed with the field-use-rate 0.84 kg acid equivalent ha(-1) of glyphosate (i.e. Roundup) herbicide. An in vitro screen for glyphosate resistance in seedlings was developed, and a 5 microM glyphosate concentration was found to reduce dry weight in GS seedlings but not in GR seedlings. The GR plants containing GFP were then hand-crossed with GS plants from eastern Tennessee under greenhouse conditions, with GS plants acting as the pollen acceptor. Resulting seed was collected and germinated for GFP fluorescence screening. Seedlings that exhibited the transgenic GFP phenotype were selected as F(1) hybrids between GR and GS horseweed. Thirty GSxGR hybrids were produced on the basis of a green-fluorescent GFP phenotype of GR plants. GSxGFP/GR F(1) hybrids produced F(2) seeds, and F(2) plants were shown to segregate for GFP fluorescence and glyphosate resistance independently. Both traits segregated at a Mendelian 3:1 ratio, indicating a single gene is responsible for each phenotype.

Conyza↗

Human tolerance and histopathologic effects of long-term administration of intranasal interferon-alpha 2.

Fifty-two healthy adults were randomly assigned interferon-alpha 2 (HuIFN-alpha 2), 8.4 X 10(6) U/day, or placebo by intranasal spray for 28 days. Symptoms, nasal examinations, and histologic analysis of nasal biopsy specimens obtained three days before and one day after exposure were evaluated under blind conditions. HuIFN-alpha 2 was associated with signs of mucosal irritation (dry mucous membranes, crusts, and friability) and/or symptoms (blood-tinged mucus) in 23% of recipients. Moderate or marked epithelial acute inflammation with ulceration occurred in 19% of HuIFN-alpha 2 recipients. Pronounced submucosal lymphocytic and mononuclear cell infiltrates developed in 58%. These histopathologic abnormalities resolved within eight weeks of stopping exposure. These results indicate that long-term or indefinite intranasal administration of HuIFN-alpha 2 at the dosages used in this study is not feasible strategy for prophylaxis of respiratory viral infections.

Administration, Intranasal↗

Malaria vectorial capacity of a population of Anopheles gambiae: an exercise in epidemiological entomology.

In order to assess the factors of malaria vectorial capacity and the daily reproduction rate, separate consideration is given to data from Kankiya, Northern Nigeria, concerning the incidence of vector-man contact (the man-biting rate), the vector's expectation of infective life, as reflected by the proportion of parous mosquitos under certain conditions, and the vector's man-biting habit, comprising the frequency of feeding and the human blood index. The main difficulty in the assessment of each of these factors was shown to be that of representative and adequate sampling, especially in a sprayed area. In order to compensate for deficiencies in the Kankiya data, especially with regard to the daily and cyclic survival-rates, the gonotrophic cycle and the effective sporogonic period, more complete published data on an Anopheles gambiae population in East Africa were examined, and extrapolations were made from these data in spite of the consequential risks involved.The results of the analysis show that the spraying of an area with DDT reduced the malaria vectorial capacity of Anopheles gambiae sp. B (the main vector of Plasmodium falciparum in the area) by an over-all factor of about 23 times. Nevertheless the basic reproduction rate of the disease is estimated to have averaged slightly over 20 in the sprayed area during the 6 months of the main transmission season. This is consistent with an observed recovery in the parasite rate, which had been reduced to a very low level by regular mass drug administration through the preceding dry season.The analysis was a tentative exercise in "epidemiological entomology" and it is suggested that in the postgraduate teaching of tropical hygiene, the epidemiological approach to entomology should be preferred to the classical morphological-bionomical approach.

Anopheles↗

Degradation of methomyl residues in frozen strawberries.

14C-Methomyl (S-methyl N-[(methylcarbamoyl)-oxy]thioacetimidate) suspended in a commercial formulation was sprayed on strawberries. At 7 and 14 days post-application, mature berries were harvested in chopped. Fresh chopped berries were extracted with methanol using a Polytron homogenizer, and the crop marc was subsequently leached with methanol, freeze-dried, and re-extracted. Portions of the fresh chopped fruit were also frozen at-20 degrees C for 1, 30, and 102 days before extraction with methanol using a Polytron homogenizer, followed by subsequent leaching of the crop marc. For fresh berries, 93.7 and 88.9% of the 14C present at harvest was extractable at 7 and 14 days post-application, respectively. Based on thin layer chromatographic analysis, methomyl represented 83.5 and 68.2% of the 14C extracted from fresh berries at 7 and 14 days, respectively. Freezing of strawberries reduced extraction efficiency and appeared to degrade methomyl. At 7 and 14 days post-application, averages of 80.9 and 77.1%, respectively, of the 14C present were extractable after frozen storage regardless of storage time. Furthermore, only about 10% of the extracted 14C was methomyl; the remainder was of unknown composition.

Chromatography, Thin Layer↗

Conidia production of Beauveria sp. by solid-state fermentation for biocontrol of Ilex paraguariensis caterpillars.

Conidia production of Beauveria sp. strain LAG by solid-state fermentation (SSF) using blends of agro-industrial residues (residual potatoes and sugar-cane bagasse) was optimized with respect to cultivation conditions and the composition of substrate mixture in Erlenmeyer flasks and column-type bioreactor. With a blend of 60 % residual potatoes and 40 % sugar-cane bagasse the optimum conditions achieved were: incubation temperature 26 degrees C, initial substrate pH 6, inoculum concentration 10(7) conidia per g substrate; optimal initial moisture of the substrate was 70 % for Erlenmeyer flasks, in column-type bioreactor (with forced aeration) the optimal initial moisture of the substrate was 65 % with airflow of 60 mL/min. The highest production (1.07 x 10(10) conidia per g dry substrate) was achieved after a 10-d fermentation. The conidia were used in laboratory assays against Thelosia camina and Hylesia sp., caterpillars that are serious pests of mate plants. The mortality of T. camina was >90 % 10 d after spraying caterpillars with 1 mL conidia suspension at a concentration 10(5)-10(8)/mL. For Hylesia sp., the mortality was 70 %, 7 d after immersion in the conidia suspension containing 108 conidia per mL. Therefore, the Beauveria sp. LAG can be considered to be an important biocontrol instrument in the prospect of the Integrated Pest Management for mate plants.

Animals↗

Effectiveness of domestic antibacterial products in decontaminating food contact surfaces.

Four commercially available antibacterial products (two wipes and two sprays) were tested under laboratory conditions on a range of food contact surfaces (wood, glass, plastic, Microban incorporated plastic). The products' effectiveness at preventing cross-contamination of Escherichia coli and Staphylococcus aureus and the influence of surface type and drying time were assessed. Survival of the bacterial culture (approximately 400 colonies per 8 cm(2)) on the above preparation surfaces was determined using an in situ nitroblue tetrazolium (NBT) method. In the absence of any antibacterial products, both bacteria survived up to 120 min on all test surfaces with glass and plastic showing no reduction in bacterial number. The order of survival is: glass>plastic>>Microban incorporated plastic>wood (<8%). The length of drying time did not affect the survival of either bacterium on glass and plastic surfaces. On wood and Microban incorporated plastic, E. coli appeared to be more sensitive to drying time than S. aureus. Only plastic appeared to affect the effectiveness of the antibacterial products, where the reduction in bacterial number was significantly lower than the other test surfaces (p<0.05). The overall results suggest the antibacterial products are effective in disinfecting food preparing surfaces, provided products instructions are carefully followed.

Anti-Bacterial Agents↗

Inhibition of bleach-induced luminol chemiluminescence.

The luminol chemiluminescence presumptive test for blood is based on the mild peroxidase activity of hemoglobin in basic peroxide solution. However, this test is subject to interference by strong oxidants, certain transition metal ions, and true peroxidases. This paper reports methods for reducing the interference caused by hypochlorite-containing bleaches. Amines such as 1,2-diaminoethane react rapidly with hypochlorite without interfering significantly with the hemoglobin-catalyzed oxidation. Thus, addition of 0.1 mol/L 1,2-diaminoethane to a standard luminol-peroxide spray lead to almost complete inhibition of hypochlorite-induced chemiluminescence while satisfactory chemiluminescence was still observed from bloodstains. If time allows, an alternative method for reducing interference from hypochlorite bleach is to wait several days until the bloodstains have dried thoroughly, by which time the hypochlorite will have decomposed.

Blood Stains↗

[Clinico-pathological studies on the effects of pulp protection (lining) under the condition with and without smear layers].

Many studies have been made of pulpal reactions to pulp protection (lining) materials have always employed a smear layer between the dentin wall and the lining materials. In this study, the author has attempted to evaluate pulpal response without a smear layer and compared effects of pulp protection (lining) with and without smear layers. Materials and methods. The experiment employed 84 vital human teeth ranging in age from 14 to 54 years. The experimental teeth were divided into 4 groups for the purposes of histopathological studies and scanning electron microscope (SEM) observation. Group C: No EDTA-treatment and lining with gutta-percha temporary material, 10 cases for histopathological study and 4 cases for SEM observation. Group TC: EDTA-treatment and lining with gutta-percha temporary material, 10 cases for histopathological study and 4 cases for SEM observation. Group P: No EDTA-treatment and lining with Protect Cement. 20 cases for histopathological study and 8 cases for SEM observation. Group TP: EDTA-treatment and lining with Protect Cement. 20 cases for histopathological study and 8 cases for SEM observation. After local anesthesia, Black's simple class I cavities were made in the experimental teeth with a diamond instrument mounted on a high-speed air turbine at room temperature with a water spray coolant. In Groups TC and TP only, an aqueous solution of 0.5% EDTA (pH 7.4) 10 ml was applied from cavity floor to dentin for 60 seconds. All cavities were then washed with distilled water, and the dentin was dried with an air stream. The floor of cavities were lined with thin layers of the following materials: Group C and TC, gutta-percha temporary material (G-C Dental Industrial Co., Tokyo, Japan). Group P and TP lining of Protect Cement which is a zinc phosphate cement containing 0.5% paraformaldehyde (Neo Dental Chemical Products, Tokyo, Japan). The restoration of each cavity was then filled with silver amalgam. Experimental teeth were clinically observed for 2 periods: short (about 14 days) and long (about 60 days) after treatment. They were then extracted under local anesthesia and prepared for histopathological study and SEM observation. Results 1. Clinical observations. During the observation period, symptoms occurred as indicated below. Group C: 2 (20%) out of 10 cases Group TC: 3 (30%) out of 10 cases Group P: None out of 20 cases Group TP: 3 (15%) out of 20 cases The only kind of clinical discomfort observed hypersensitivity to cold water. 2. Clinical evaluations Group C: 10 cases (100%) were good.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗

Immobilization of fine particles on lactose carrier by precision coating and its effect on the performance of dry powder formulations.

The feasibility of immobilization of fine particles on a lactose carrier by precision coating and producing carrier particles of different surface roughness from the same core was explored. A relationship between the resultant surface roughness of the carrier and the in vitro deposition pattern of salbutamol sulfate was established. Lactose carrier particles in the precision coating chamber were spray coated with liquid suspensions consisting of micronized lactose dispersed in isopropyl alcohol (IPA) and/or water mixtures. The surface-modified lactose particles were fractionated and then characterized by laser diffraction for size, image analysis for shape, and scanning probe microscopy for surface roughness. The in vitro deposition pattern of salbutamol sulfate from the drug-lactose mixtures was determined with the twin-stage glass impinger and expressed as the fine particle fraction and dispersibility of the drug. Immobilization of fine particles on carrier particles was feasible by the precision coating process as shown by the scanning probe topographs and the roughness values of the carrier particles. Generally, more discrete fine particles were deposited on the carrier surface and a higher surface roughness was seen when the spray suspension consisting of a higher proportion of IPA was used. A significant correlation was found between the fine particle fraction of salbutamol sulfate with the roughness of lactose. This relationship established between the in vitro drug deposition pattern and the microscopic surface roughness of the carrier would be helpful in the optimization of drug delivery to targeted areas in the lungs.

Albuterol↗

Regulation of summer dormancy by water deficit and ABA in Poa bulbosa ecotypes.

BACKGROUND AND AIMS: Survival of many herbaceous species in Mediterranean habitats during the dry, hot summer depends on the induction of summer dormancy by changes in environmental conditions during the transition between the winter (growth) season to the summer (resting) season, i.e. longer days, increasing temperature and drought. In Poa bulbosa, a perennial geophytic grass, summer dormancy is induced by long days, and the induction is enhanced by high temperature. Here the induction of summer dormancy in a Mediterranean perennial grass by water deficit under non-inductive photoperiodic conditions is reported for the first time. METHODS: Plants grown under 22/16 degrees C and non-inductive short-day (9 h, SD) were subjected to water deficit (WD), applied as cycles of reduced irrigation, or sprayed with ABA solutions. They were compared with plants in which dormancy was induced by transfer from SD to inductive long-day (16 h, LD). Responses of two contrasting ecotypes, from arid and mesic habitats were compared. Dormancy relaxation in bulbs from these ecotypes and treatments was studied by comparing sprouting capacity in a wet substrate at 10 degrees C of freshly harvested bulbs to that of dry-stored bulbs at 40 degrees C. Endogenous ABA in the bulbs was determined by monoclonal immunoassay analysis. KEY RESULTS: Dormancy was induced by WD and by ABA application in plants growing under non-inductive SD. Dormancy induction by WD was associated with increased levels of ABA. Bulbs were initially deeply dormant and their sprouting capacity was very low, as in plants in which dormancy was induced by LD. Dormancy was released after 2 months dry storage at 40 degrees C in all treatments. ABA levels were not affected by dormancy relaxation. CONCLUSIONS: Summer dormancy in P. bulbosa can be induced by two alternative and probably additive pathways: (1) photoperiodic induction by long-days, and (2) water deficit. Increased levels of endogenous ABA are involved in both pathways.

Abscisic Acid↗

[Auguste Lumière, pioneer of the modern cicatrization].

At the "Grand Café" in Paris, on december 28, 1895 Louis and Auguste Lumiere displayed the cinematograph, a technical innovation that revolutionized the nascent motion picture. It was the first public projection of a film. While Louis continues his work on pictures and invents autochrome plates for colour photography, Auguste focused his interests on biology and medicine. Since Ambroise Paré, few doctors have been interested in the healing process. Although Carrel and Lecomte Du Nouy published the first studies in the early twentieth century, Auguste Lumière was a pioneer in the modern research and treatment of wounds. He applied the principles of experimental medicine. In his research he used 44 dogs to study the healing speed and the scar quality in certain areas and under general conditions. In the winter of 1914-1915 he studied in Lyon several hundred wounds of war casualties. In 1922 he established and published in a marvellous book the principles of normal healing. In the department of Pr Leon Bérard he was shocked by the fetidness of the wards where the dried bandages were changed once a week. In 1915 he perfected a revolutionary sterilized "treatment-bandage" consisting of 2 mm stitched gauze saturated with Vaseline and Perou's balsam: the "Tulle Gras. In order to disinfect wounds, he used an iodized solution, sprayed in little droplets. The lives of Auguste and Louis Lumière were full of projects and inventions. When Auguste died in 1954 he had registered more than one hundred patents.

Cicatrix↗