Cotton Wool Plugs Research Articles

Development and evaluation of 3-dimensional printed models of the human tracheobronchial system for training in flexible bronchoscopy.

Training and assessment of proper skills in flexible bronchoscopy are major educational goals for cardiothoracic residents. Therefore, we developed 3-dimensional (3D) printed models of the human tracheobronchial system for training and assessment of cardiothoracic residents in flexible bronchoscopy. Three models of normal (size/shape) human tracheobronchial anatomy were generated using a commercially available 3D printer. Ten residents (inexperienced: Group 1; experienced: Group 2) participated in this study with an experimental setting of initial assessment (Model 1), training (15 min, Model 2) and post-training assessment (Model 3). The time needed for flexible bronchoscopy assessment of randomly assigned ostia was recorded before and after training. Additionally, the time for retrieval of a foreign body from the tracheobronchial system was measured before and after training. The average time for intubation of a given ostium (Model 1) at initial assessment was 88 s for Group 1 and 38 s for Group 2 (P < 0.0001). Following training, there was a significant reduction in time for intubation of a given ostium (Model 3) in both groups (P < 0.0001). However, the initial difference between experienced and inexperienced residents was no longer present following training. Additionally, the time for retrieval of a foreign body (cotton wool plug) from the tracheobronchial system was significantly reduced following training in both groups. Accurate models of the human tracheobronchial system can be generated from representative patient images using 3D engineering software and 3D printing technology. With these models, residents can be effectively trained in flexible bronchoscopy with significant improvement in their proficiency and handling capability.

Influence of culture vessel volume and ventilation on in vitro culture and adenosine accumulation of Anoectochilus setaceus Blume

Anoectochilus setaceus is a medicinal plant used as a traditional medicine as well as nutritious products for health care in China and many Asian countries. In conventional propagation, the the vessel type, material and volume lead to differences in the moisture content between the internal and external conditions which result in great impact on the quality of in vitro plantlets as well as subsequent growth at nursery. In this study, several factors affecting the multiplication and regeneration of A. setaceus cultured in vitro were investigated. The highest percentage of shoot regeneration (52.88%) from ex vitro stem nodes was obtained when explants were cultured on SH medium supplemented with 1 mg/l BA, 30 g/l sucrose with cotton wool plug as the substrate and pH of the medium was adjusted to 5.8 prior to autoclaving. In the present study, culture vessel volume and ventilation culture conditions indicated to have effect on shoot quality. Results showed that 3-liter Erlenmeyer flasks in combination with ventilation caps resulted in better shoot growth and development (shoot height: 10.75 cm; 9.45 leaves per shoot; fresh- and dry- weight of 2.45 and 0.219 g per shoot, respectively; leaf diameter: 2.85 cm and SPAD: 39.99). Results of chromatography (TLC) analysis indicated that explants gave the same Rf value as that of authentic Adenosine. Qualifying Adenosine using TLC showed that extracts of shoots cultured on solid and liquid medium (ventilation plastic bag), and that of shoots cultured in 3-liter vessel with liquid medium (with and without ventilation) gave the same pattern in the respects of color and Rf value.

Screening of Different Hevea brasiliensis Clones Based on the Reaction to Phytophthora Bark Rot

Disease conditions caused by Phytophthora species are common on rubber (Hevea brasiliensis) in all rubber-growing countries. Bark rot is the most economically damaging disease of the tapping panel of the rubber tree, leading to the cessation of tapping during the monsoon months in rubber plantations. To overcome this situation, the disease screening programs aiming disease resistant/tolerant clones are continually carried out. The current study attempted to evaluate the reaction of different clones of H. brasiliensis against the Phytophthora bark rot in order to recommend a suitable planting material for the industry. Forty clones of H. brasiliensis were screened at the bud wood nursery of Kuruwita substation of Rubber Research Institute of Sri Lanka during South West monsoon, 2014. Each clone consisted ten bud wood plants and in each bud wood plant, three branches were used for the inoculation. These plants of different clones were artificially inoculated with a standard spore suspension of Phytophthora meadii. This was prepared by scraping the sporangia on the surface of culture plates into sterile distilled water and the final concentration was adjusted to 1x104 spores per ml. At the inoculation, the bark of the selected branches was removed with a cork borer and the wood was exposed. A sterile absorbent cotton wool plug saturated with 2 ml of the zoospore suspension was placed on the exposed wood of the plant. The cotton wool plugs were taken in sterile Petri dishes to the experimental site and a freshly-prepared zoospore suspension was used. As the control, in each of the bud wood plant tested, one branch was inoculated with a cotton wool plug with sterile distill water. After the inoculation, the inoculated portions of the branch were sealed off with budding tape in such a manner to ensure aeration. Four weeks after the inoculation, the exposed lesions were traced on to tracing papers, after removing the bark and the area under the lesions were measured with a plannimeter. The area under the lesion was assumed to be inversely proportional to the resistance level of the relevant rubber clones towards the P. meadii infection. The area of the lesion resulted after each treatment was subjected to analysis of variance in SAS statistical software. The results of the trial carried out suggest the possibility of categorizing the screened clones into three clusters. The clones RRISL 222, RRISL 220, RRISL 208, RRISL 219, RRIM 600, RRIC 102, RRIM 717 and PB 235 are among the most resistant clones while the clones, PB 255, RRISL 206, RRISL 225, RRISL 201, RRIC 130, RRISL 211, RRISL 205 and RRIC 131 are among the most susceptible clones against Phytophthora bark rot. Therefore, it can be concluded that, the screened clones were showing differential reaction to the Phytophthora bark rot under bud wood nursery conditions. Keywords: Phytophthora bark rot, Hevea brasiliensis, Clonal screening

Ex vitro and in vitro Paphiopedilum delenatii Guillaumin stem elongation under light-emitting diodes and shoot regeneration via stem node culture

Paphiopedilum spp. are high value horticultural crops; however, success in Paphiopedilum spp. culture is still limited. It is therefore necessary to find out adequate solutions to improve the culture techniques of these recalcitrant species. In the present study, ex vitro shoots exposed to LEDs for shoot elongation and in vitro multiplication of P. delenatii from single nodes were investigated. One-month-old ex vitro shoots with 1.5–2.0 cm length were grown under various light conditions including monochromatic blue and red LEDs, mixtures of blue and red LEDs, and the darkness for investigations of the shoot elongation. The results indicated that the best stem elongation was obtained under monochromatic blue LED (100B) after 4 months of culture. The highest shoot regeneration rate (45 %) was also recorded in shoots cultured on liquid SH medium containing 30 g l−1 sucrose, 1.0 mg l−1 TDZ and 0.3 mg l−1 NAA with cotton wool plug as the substrate and exposed to 100B after 45 days. P. delenatii young shoots, which had formed 5 leaves, were placed into SH medium supplemented with 0.5 mg l−1 BA, 0.5 mg l−1 NAA, 30 g l−1 sucrose, and 1 g l−1 activated charcoal in the darkness for stem node elongation before transferred into greenhouse. After 120 days, the average shoot length was 10.5 cm, and five new leaves and five single nodes per shoot were observed. These shoots then were maintained under fluorescent light for 60 days. Although the shoots regenerated new leaves, no new node was observed. After 180 days of culture, each shoot was cut into five single nodes, and cultured on fern fibers. These shoots showed to grow vigorously after 12 months.

EFFECTS OF PHOTOMIXOTROPHIC CONDITIONS AND TYPE OF CULTURE VESSEL CLOSURE ON ANACARDIUM OTHONIANUM RIZZ. GROWN IN VITRO

Anacardium othonianum Rizz. is a species of fruit tree from the Brazilian cerrado; the economical exploitation of which is a viable alternative for local farmers. The present study aimed to evaluate the influence of sucrose and the type of culture tube closure on the in vitro leaf anatomy of A. othonianum. Shoots were transferred to glass tubes containing woody plant medium supplemented with 5.9 µM indole-3-butyric acid, 4 g L-1 agar and 2 g L-1 activated charcoal, in the absence or presence of sucrose (3%). The tubes were closed with plastic caps, plastic caps wrapped with PVC film, or with cotton plugs. The anatomical variables were larger under heterotrophic conditions, but tended to decrease when a photomixotrophic stimulus was applied. However, by maintaining the plantlets under photomixotrophic conditions in tubes closed with cotton wool plugs, the values of the anatomical variables diminished, thus improving the chances of success in the subsequent stages of propagation. The results obtained revealed that A. othonianum exhibited a considerably adaptive plasticity. By diminishing the values of the anatomical variables, cotton wool closures provided not only an adequate environment for the growth of plantlets in vitro under photomixotrophic conditions.

Negative impact of the noseclip on high-frequency respiratory impedance measurements

The noseclip is conventionally used in lung function testing to prevent leakage via the nasal compartments. However, some subjects exhibit a velum-opening reflex which may affect results. We performed forced oscillation measurements at frequencies (8-256 Hz) that include the first antiresonance, comparing the noseclip with a cotton wool nose plug to eliminate upper airway contribution. Three sets of measurements were made in 18 adults: with and without noseclip, and with cotton wool. Velum opening during noseclip measurements was monitored using a nasal pressure transducer. A significantly greater proportion of subjects produced a characteristic distortion to the first antiresonance with the noseclip than with either no noseclip or with cotton wool. Distortion of the spectrum coincided with the transmission of oscillations into the nasal cavity. Thus, the noseclip cannot be used in high-frequency forced oscillation measurements because of the velum reflex. The cotton wool plug offers a simple alternative. This effect has unknown impact in other lung function tests.

Presentation and management of aural foreign bodies in two Australian emergency departments

To survey and compare the type and management of foreign bodies found in adult and paediatric ears presenting to an Australian otorhinolaryngology and a general ED. Retrospective case study with data collated from two centres. Chart reviews of a total of 330 patients presenting with aural foreign bodies to the ED of the Royal Victorian Eye and Ear Hospital and the ED of The Bendigo Hospital, both situated in the state of Victoria, Australia, were surveyed for patient demographics, foreign body description and referral and removal pattern. Two hundred and seventeen adults and 113 children were included in the study. The most common foreign bodies in children were beads, cotton tips, insects and paper, and in adults cotton tips, insects, cotton wool and silicone ear plugs. Flying insects were far more common in the Australian population than cockroaches found in surveys in other countries. Children were significantly more likely to have initially been seen by their Local Medical Officer than adults (P < 0.001) and to require a general anaesthetic for removal of the object(s) (P < 0.001). Adults were more likely to have associated otitis externa at the time of presentation (P < 0.05). Aural foreign bodies are a frequent presentation to the ED. Recognition of patients requiring early specialist referral is important. Adults present with a different profile of aural foreign objects to children and require different management. The use of cotton tips or cotton wool in the external ear canal and silicone ear plugs should be discouraged.

A device for preparing cotton wool plugs

A device for preparing cotton wool plugs

Simultaneous Purification of Merozoites and Schizonts of Eimeria tenella (Apicomplexa) by Percoll Flotation and Assessment of Cell Viability with a Double Fluorescent Dye Assay

The asynchronous development of Eimeria tenella in orally infected chickens makes it possible to purify second generation merozoites (meros) and shizonts from a single mucosal homogenate. After centrifugation in 30% Percoll in phosphate-buffered saline (Percoll-PBS), debris, villi, and schizonts float, whereas meros and erythrocytes are pelleted. Erythrocytes are lysed by a mild hypotonic shock; meros are filtered through a cotton wool plug and collected by centrifugation. The 30% Percoll-PBS supernatant fraction is diluted to 25% Percoll-PBS and centrifuged to sediment mature schizonts. By repeated slow-speed centrifugation, schizonts are separated from nuclei and small-sized debris. In less than 3 hr, 8.8 +/- 2.3 x 10(8) meros and 7.2 +/- 3.9 x 10(6) schizonts are collected from 10 infected chickens. Contamination with host material is 2% for meros but variable for schizonts. For the assessment of cell viability, ethidium bromide (EB) and acridine orange (AO) have been used as markers for dead and living cells, respectively, in a single step method. More than 95% of the schizonts and meros accumulate AO and no EB, whereas lysed erythrocytes and all cells hosting a schizont are permeable to EB. After incubation of meros and schizonts in synthetic media with [5,6- 3H]uracil, label accumulates in the perchloric acid-soluble and -insoluble fractions, indicating transport, salvage, and incorporation of the pyrimidine precursor in nucleic acids. If stored on ice, meros and schizonts retain metabolic activity for at least 5 hr, but metabolism declines rapidly during incubation at 41 C.

Application of sialidase antibodies for the diagnosis of clostridial infections

Two immunological methods, a sialidase-inhibition test and an ELISA, had been developed for a species-specific detection of sialidases (EC 3.2.1.18) secreted by growing cells of Clostridium perfringens, C. septicum, and C. sordellii. These assays were applied to samples from the infected tissues and cotton wool plugs soaked with wound exudate from patients suspected to be suffering from gas gangrene. The results from 72 patients were compared with bacteriological investigations of 67 homologous samples. From these, 35 patients were found to be infected with one or two of the clostridial species: thirty patients contained C. perfringens, six samples showed an immunologically positive reaction for C. septicum and eight for C. sordellii. In the case of C. perfringens, a high degree of coincidence between the immunological and the bacteriological analyses was obtained. However, in infections with C. septicum or C. sordellii the bacteriological and immunological tests did not agree well. The simple and rapid sialidase inhibition test or the slightly more time-consuming ELISA, which even detects low quantities of sialidase, can be applied for the specific diagnosis of infections caused by C. perfringens, thus allowing a species-specific detection of this bacterial species in two or six hours, respectively, even at an early stage of infection. This early diagnosis is a prerequisite for a specific and life-saving therapy of this severe disease.

Quantitative 99mTc-DTPA Scintigraphy for Determination of Maxillary Sinus Drainage following Caldwell-Luc Surgery

Nine maxillary sinuses of 8 patients who had undergone Caldwell-Luc surgery (CWL) were injected with 100-125 microCi 99mTc-DTPA in 0.2 ml from the gingivo-buccal sulcus, passing through the canine fossa window. Sinus half-emptying times and percent contribution of the natural ostium (NO) and the naso-antral window (NA) to the clearance from the sinus were calculated, using time-activity curves as well as the activity of cotton wool plugs placed into the middle and lower conchae. Mean half-emptying times in patients in whom the mucosa had been removed were shorter than those in patients in whom it had been left in place. In the former group percent drainage through the NO was higher than that through the NA whereas in the latter group the opposite was the case. These findings are consistent with the thesis that if the mucosa is retained, the cilia continue their sweeping action towards the NO but if it is removed the NA gains importance in the drainage. This method is promising for the evaluation of maxillary sinus drainage following CWL.

An on‐column capillary gas chromatographic method for the analysis of synthetic pyrethroid residues on fish eggs

AbstractA sensitive and reproducible residue method is described for the determination of cypermethrin and deltamethrin in fish eggs. The limit of determination of 0.0005 mg kg−1 is achieved using only a very small sample size; typical sample weights lie in the range of 0.1‐1 g of fathead minnow or trout eggs. The method involves tissue homogenization (tube homogenizer) followed by hot acetonitrile extraction, then sequential C8, aluminum oxide, and silica gel clean‐up. The clean‐up is carried out in glass columns using cotton wool plugs in order to minimize potential sample contamination by plasticizers. Residues are determined by capillary chromatography using automated on‐column injection with electron‐capture detection. Confirmation of residues by gas chromatography‐mass spectrometry using selected ion monitoring (SIM), is also described.

Air sampling of volatile sex pheromone components in a closed jar

A cotton wool plug, used as the source for pheromone release, was placed in closed 1-quart Mason jars, either at the mouth or at the rear of the jar. Air sampling of the two components of the sex pheromone (total 2.2 mg at the source) of the almond moth (Ephestia cautella) female showed that the saturation period near the source in still air was 20-22 hr and that far from the source was 40-50 hr, reaching a level of less than 1 ng/ml air. The ratio between the components (Z,E)-9,12-tetradecadienyl acetate, designated D, and (Z)-9-tetradecenyl acetate designated M, in the air was close to the original ratio for both sampling sites, albeit somewhat richer in the more volatile (Z)-9-tetradecenyl acetate (source 77.0∶23.0 D∶M, air 73.0- 74.3∶27.0-25.7; source 80.1∶19.9, air 77.6∶22.4; source 25.1∶74.9, air 23.9∶76. 1 D∶M). The total amount of pheromone per milliliter of air was two to three times larger near the source than far from it at the early stages of the evaporation and saturation process. When the amount of pheromone applied to the source was tripled (7 mg), the amount far from the source was almost tripled, or the saturation time was cut by factor of two to three.

Pneumonia following experimental bronchial obstruction in sheep

Five of 7 sheep in which the bronchi supplying the right apical lobe of the lung were obstructed with a cottonwool plug developed pneumonia. Large numbers of bacteria were isolated from 4 of the 5 pneumonic lungs. Only minor pulmonary lesions, which are common in sheep on pasture, were observed in 5 sham operation and 5 control sheep. These results support a role for airway obstruction in compromising the antimicrobial defences of the lungs in naturally occurring bacterial pneumonias of sheep.

A statistical comparison of two culturing methods for enumerating sulfate-reducing bacteria

The addition of alkaline pyrogallol-soaked cotton wool plugs has been used by other workers to remove oxygen from the headspace gas in culture tubes for the growth of sulfate-reducing bacteria (SRB). This study compares the enumeration fo SRB using the most probable number (MPN) method in tubes with and without the pyrogallol plugs. In both cases, the liquid medium contained two iron finishing nails which help reduce the redox potential of the medium. For each of the 25 samples from oil fields, cooling water systems and natural environments, the time-consuming method using pyrogallol plugs in screw cap tubes yielded virtually the same MPN values as the same method without the plugs and using Kaput® closures on the tubes. However, the pyrogallol plug method, which requires approximately 10-fold more technician time, was superior for pure culture enumeration and in cases where SRB greatly outnumber heterotrophs.

An evaluation of two methods of substrate alkalinization for the identification of Bordetella avium and other similar organisms

The effect of using two different techniques for the detection of substrate alkalinization by Bordetella avium and reference strains of Alcaligenes faecalis and B. bronchiseptica was evaluated. The techniques used were those described by Otto and Pickett and Hinz et al. Each test was in tubes sealed by either screw caps or cotton wool plugs. The alkalinization patterns obtained depended upon both the technique and the type of seal used.

Airborne infection in hospital

Before the era of microbiology certain diseases were thought to be caused by noxious exhalations (‘miasmata’) arising from putrescent organic matter. Gregory (1788), for example, placed miasmata at the head of his list of ‘general causes of fever’, and also included among these causes ‘a certain state of the air which produces epidemical fevers, from causes not always ascertained’. The transfer of infection through the air, which had been recognized on epidemiological grounds, gained support at the beginning of the microbiological era from Pasteur’s demonstration that the sterilized contents of narrow-necked flasks became contaminated by bacteria admitted with air which was sucked in through the neck; the bacteria could be kept out by a cotton wool plug. Pasteur also showed that bacteria were abundant in the air of populated environments but scanty in mountain air or uninhabited rooms. The airborne transfer of bacteria and other microbes from an infected person or some other source, causing disease in previously uninfected persons, can occur only if the pathogens are expelled to the exterior in sufficient numbers, if they are able to survive in a virulent condition outside the body for an appreciable time, and if they are then able to gain access to and multiply in the susceptible tissues of a potential host. Tubercle bacilli were recognized in the early days of bacteriology to have such properties; Cornet reported in 1889 that they could survive in dried sputum and held that tuberculous infection was transmitted on dust particles arising from dried sputum (Wilson and Miles, 1975). Flugge (1899) held that droplets expelled from the respiratory tract were important vehicles; such droplets could be projected by a sneeze to a distance of several feet before they fell to the ground, and might cause infection if inhaled by someone within range. A third way in which microbes were envisaged to cause airborne infection was when they were carried as droplet nuclei (Wells and Wells, 1936), i.e. particles consisting of the residue left after evaporation of water from minute droplets which remained suspended in air. Dispersal may be promoted by sneezing and, to a lesser degree, by coughing (Lidwell, 1974); few organisms are dispersed during ordinary breathing or talking (Duguid, 1946). The numbers of organisms dispersed by different people when talking is variable, but a sneeze could disperse as many as 105-lo6 droplets.

Use of a single infusion bottle to culture and prepare potentially hazardous microorganisms for biochemical analysis. Culturing on solid media.

A procedure is described to culture microorganisms under aerobic and anaerobic conditions in infusion bottles internally coated with a solid agar medium, in view of headspace sampling of volatile components or extraction of cellular constituents. This method is far less laborious than conventional petri-dish procedures and reduces the risk of contamination. Biochemical analysis of microorganisms usually involves time-consuming and laborious procedures including sterilization of media, inoculation, culturing, killing, harvesting, washing, freeze-drying, extraction and, finally, sampling for separation and characterization of components (Booth, 1971; Constantinescu, 1974). To simplify the procedure, a ‘single bottle technique’ was introduced for liquid media (Weijman, 1978), using regular infusion bottles as applied in blood banks and hospitals. The present paper describes a similar technique for use with agar-containing solid media, as an alternative for or an addition to the use of petri dishes, Roux bottles or roll-tubes (Hirsch, 1948). Procedure: Infusion bottles made of borosilicate glass were used with the following specifications: 500 ml capacity, 21 cm in height and 7.7 cm outside diameter. Bottles containing 50–150 ml medium with 3% agar (w/v) were autoclaved for 20 min at 120°C and cooled to ambient temperature. During cooling the bottles were rotated in a horizontal position at about 50 rpm to allow smooth and gradual coating of the inner surfaces. Subsequently, the flasks were inoculated and incubated (Fig. 1). The bottles can be closed with cotton wool plugs

The retention efficiency of cotton wool plugs used as bacterial filter

The retention efficiency of cotton wool plugs used as bacterial filter

The assessment of air-inlet filters for intravenous infusions in glass bottles

Glass infusion bottles require the influx of air into the containers to replace fluid during administration. A non-absorbent cotton wool plug, situated in the air-inlet set, acts as a filter to remove airborne micro-organisms. an enclosed air space artificially contaminated with viable bacterial spores was used to assess the contamination of intravenous infusions from an airborne source. Only small numbers of spores gained access to the infusion fluids when containers were used with commercially made air-inlet sets. Removal of the filter permitted the entry of spores, the numbers being related to the concentration present in the external air. The efficiency of cotton wool plugs was related to the weight of cotton wool in the air-inlet set. The compression applied to the cotton wool also significantly influenced filter efficiency. Although air-inlet sets were challenged with much higher levels of airborne contamination than would be expected in a hospital environment, results indicate that the air-inlet set should contain sufficient cotton wool. The compression of the filter material should also be considered.