Serious childhood injuries caused by air guns.

OBJECTIVE: To determine the severity of nonfatal injuries to children caused by air guns and pellet guns. DESIGN: Case series (hospital chart review). SETTING: Inpatient wards of the Children''s Hospital of Eastern Ontario. PATIENTS: All children under 18 years of age admitted to the hospital from Jan. 1, 1979, to Dec. 31, 1989, under ICD code E917, E922, E955, E965, E970 or E985 who had suffered air gun injuries. MAIN OUTCOME MEASURES: Personal data, circumstances of event and clinical data. RESULTS: The 43 children (37 boys) had a median age of 12 years. The circumstances of the accident were known in 20 cases: 17 children were playing and 3 were cleaning the gun when it went off. Four children thought the gun was unloaded. In five cases the bullet ricocheted into the eye. Nine injuries were self-inflicted. Injury was to the extremities in 21 (49%), the eyes in 15 (35%) and the head and neck in 7 (16%). The median length of hospital stay was 4 days. Six children had long-term disabilities, all the result of eye injuries; two had cataract surgery, and four required enucleation of the eye. CONCLUSIONS: Air guns can cause serious injury to children. Their sale needs to be banned or at least carefully regulated.     

Comparison of a laboratory and a production coating spray gun with respect to scale-up

A laboratory spray gun and a production spray gun were investigated in a scale-up study. Two Schlick spray guns, which are equipped with a new antibearding cap, were used in this study. The influence of the atomization air pressure, spray gun-to tablet bed distance, polymer solution viscosity, and spray rate were analyzed in a statistical design of experiments. The 2 spray guns were compared with respect to the spray width and height, droplet size, droplet velocity, and spray density. The droplet size, velocity, and spray density were measured with a Phase Doppler Particle Analyzer. A successful scale-up of the atomization is accomplished if similar droplet sizes, droplet velocities, and spray densities are achieved in the production scale as in the laboratory scale. This study gives basic information for the scale-up of the settings from the laboratory spray gun to the production spray gun. Both spray guns are highly comparable with respect to the droplet size and velocity. The scale-up of the droplet size should be performed by an adjustment of the atomization air pressure. The scale-up of the droplet velocity should be performed by an adjustment of the spray gun to tablet bed distance. The presented statistical model and surface plots are convenient and powerful tools for scaling up the spray settings if the spray gun is changed from laboratory spray gun to the production spray gun. Published: January 19, 2007     

Guidelines for pharyngostome closure

The reconstructive procedure for pharyngostome closure includes single-stage restoration in three steps: lining, intermediate layer, and covering. The lining repair is the key factor to the successful outcome of the operation. Three clinical situations may be distinguished. First, the mucosa is sufficient to restore a new gullet. In this case, it is widely undermined and sutured along the midline without any tension. Second, the mucosa is only partially sufficient. The same procedure as above is adopted to close the lower two-thirds of the pharyngostome, while an advancement flap is outlined from the base of the tongue to restore the upper third. Third, the mucosa is not sufficient. A musculocutaneous flap solves the problem. Reconstruction of the intermediate layer involves rotation of one (or both) sternomastoid muscle(s), if present. The possibilities for coverage include a submandibular flap, a thoracoacromial flap, and/or musculocutaneous flaps. By following these guidelines, the authors have successfully closed 37 pharyngostomes.     

Validation of the dorsal air pouch model to predict and examine immunostimulatory responses in the gut

Aims:  To validate the use of the air pouch system to predict and examine early immune responses induced by the presumptive probiotics Lactobacillus paracasei subsp. paracasei B112, DC205, DC215 and DC412 strains in the gut mucosa.
Methods and Results:  Only the DC412 strain interacted strongly with the cells forming the air pouch lining tissue and induced early innate immune responses such as polymorphonuclear (PMN) cell recruitment, phagocytosis and tumour necrosis factor alpha (TNF-α) production that equal the respective responses induced by the probiotic Lactobacillus acidophilus NCFB 1748. The strains exhibiting strong immunoregulatory activity in the air pouch also interacted strongly with the gut-associated lymphoid tissue (GALT). The strain DC412 exerts its effect on the intestine through stimulation of Toll-like receptor (TLR)2/TLR4-mediated signalling events leading to secretion of a certain profile of cytokines in which gamma interferon (IFN-γ), TNF-α, interleukin (IL)-6 and IL-10 are included. The probiotic Lact. acidophilus NCFB 1748 induces the same cytokine profile in addition to IL-12B, and this response is potentially mediated by the synergy of TLR2 and TLR9.
Conclusion:  The strain DC412 possesses the in vitro and in vivo characteristics of a probiotic micro-organism.
Significance and Impact of the Study:  The dorsal mouse or rat air pouch may be used as an alternative and rapid method for the initial discrimination and selection of potential probiotic Lactobacillus strains.     

Lower eyelid reconstruction with a conchal cartilage graft

A conchal cartilage graft without skin or mucosa was used as a posterior lining for lower eyelid reconstruction in seven patients. The raw surface of the graft was smooth enough to cause no corneal irritation and was epithelialized from the surrounding mucosa about 3 to 4 weeks after the operation. The lower eyelid reconstructed in this method produced a stable lid margin.     

Ocular Injuries Caused by Airgun Pellets: An Analysis of 105 Cases

One hundred and five cases of airgun pellet injuries of the eye have been analysed. The average age was 14 and the male to female ratio 7·5:1. Forty-five patients had final visual acuities of 6/18 or less in the injured eye and 19 of these had the eye removed. The two main causes for poor vision were retinal damage and cataract. One patient became completely blind after sympathetic ophthalmitis arising 11 years after the injury. The pellet lodged in the orbit in 14 cases and three of these, together with one who had an intraethmoidal pellet, were investigated for abnormal lead levels in blood and urine. The results were normal.The circumstances of the injury were obtained in 12 cases and most involved careless handling of a gun. Instruction of children and parents in schools and on television, rather than stricter legislation, is suggested as a means of prevention.     

The disappearance of muntjac (Muntiacus reevesi) and roe deer (Capreolus capreolus) pellet groups in a pine forest of lowland England

Reliable knowledge of the disappearance rate of faecal pellets is essential for converting pellet density to deer density when using standing-crop pellet-group counts. Disappearance of muntjac and roe deer pellet groups was monitored in four growth stages of a pine forest of lowland England over a 15-month period. Time to disappearance of the pellet groups (days) of both species significantly differed between habitats and months; it was shorter in late summer to early autumn and in habitats with more ground vegetation. Muntjac pellet groups disappeared more quickly than roe deer pellet groups. Time to disappearance of roe deer pellet groups was negatively correlated with air and grass temperature in pre-thicket and pre-fell habitats, while time to disappearance of muntjac pellet groups was negatively correlated with frequency of rainfall and positively correlated with the run of wind (air passage over a site within a 24-h period measured in km) in pre-thicket habitats. It is the time of the standing-crop pellet-group counts and the disappearance rate of pellet groups deposited in different months and habitats that determine the appropriate method for conversion of pellet-group density to deer density.     

Menetrier's disease in a rhesus monkey (Macaca mulatta).

Gross and microscopic features closely resembling those found in Menetrier's disease in man are described in a 20-month-old rhesus monkey. The gastric lining was characterized by greatly enlarged rugae caused by mucosal hypertrophy and hyperplasia along with outfolding of the muscularis mucosa and the submucosa. The mucosa and submucosa were infiltrated with inflammatory cells, mainly lymphocytes and plasma cells.     

The dermis-prelaminated scapula flap for reconstructions of the hard palate and the alveolar ridge: a clinical and histologic evaluation.

Ideal reconstructions of complex defects in the midface require the restitution not only of bone and soft tissue, but also of a thin and durable lining of the oral cavity. So far, split-thickness skin grafts, intestinal grafts, and in vitro cultured mucosal grafts have been used for the reconstruction of the oral lining. The use of skin as a substitute for oral mucosa is controversial because contraction, hair growth, maceration, and dysplastic changes can occur. This clinical and histologic study was performed to evaluate the suitability of dermis as a substitute for oral lining. Twelve complex defects of the midface were reconstructed with dermis-prelaminated scapula flaps. A bony flap from the lateral border of the scapula was prepared, and osseointegrated implants were placed. The bone flap was then prelaminated with dermis and covered with a Gore-Tex membrane to prevent adhesions. The composite flap was transferred to the midface 2 to 3 months later. The oral lining of the flap was evaluated clinically and histologically at 2, 4, and 6 weeks and at 3 to 41 months after the reconstruction. In all patients, the reconstructed bone was covered with a thin and lubricated surface without hair growth. None of the patients showed any signs of maceration. Histologically, these findings corresponded to a keratinized stratified squamous epithelium with highly developed connective-tissue papillae. These features closely resemble those of the normal mucosa of the hard palate and the gingiva. Thus, dermis prelamination is an effective method for reconstructing the mucosa of the alveolar ridge and the hard palate.     

Ozone and the lung: a sensitive issue

Ozone is a powerful oxidant and toxic air pollutant. As a gaseous pollutant, its primary target tissue is the lung and breathing slightly elevated concentrations of ozone results in a range of respiratory symptoms. These include decreased lung function and increased airway hyper-reactivity in 10-20% of the healthy population. Moreover, those with conditions such as asthma and chronic obstructive pulmonary disease (COPD) generally experience an exacerbation of their symptoms. Together, these observations suggest that certain individuals are particularly susceptible to this oxidant gas. The primary goal of this review is to examine the basis of this increased sensitivity. Ozone is a highly reactive gas that is consumed by reactive processes on reaching the first interface in the lung, the lung lining fluid compartment. Reactions between ozone and antioxidants tend to dominate in this compartment and these are generally thought of as beneficial, or protective interactions. In those instances when ozone reacts with other substrates in lung lining fluid such as protein or lipid, secondary oxidation products arise which transmit the toxic signals to the underlying pulmonary epithelium. The rules that govern the balance between beneficial and detrimental interactions in the lung lining fluid compartment are not well established but these may contribute, in part, to sensitivity. On reaching the lung surface, secondary oxidation products arising from ozone initiate a number of cellular responses. These include cytokine generation, adhesion molecule expression and tight junction modification. Together, these responses lead to the influx of inflammatory cells to the lung in the absence of a pathogenic challenge. Moreover, lung permeability is increased and oedema develops. The nature and extent of these responses are variable and often not related within an individual. Thus, although an improved appreciation of the general mechanism of action of ozone has been attained in recent years, the basis for individual susceptibility is still unclear.     

Biotransformation of three pharmaceutical active compounds by the fungus Phanerochaete chrysosporium in a fed batch stirred reactor under air and oxygen supply

White-rot fungi are a group of microorganisms capable of degrading xenobiotic compounds, such as polycyclic aromatic hydrocarbons or synthetic dyes, by means of the action of extracellular oxidative enzymes secreted during secondary metabolism. In this study, the transformation of three anti-inflammatory drugs: diclofenac, ibuprofen and naproxen were carried out by pellets of Phanerochaete chrysosporium in fed-batch bioreactors operating under continuous air supply or periodic pulsation of oxygen. The performance of the fungal reactors was steady over a 30-day treatment and the effect of oxygen pulses on the pellet morphology was evidenced. Complete elimination of diclofenac was achieved in the aerated and the oxygenated reactors, even with a fast oxidation rate in the presence of oxygen (77% after 2 h), reaching a total removal after 23 h. In the case of ibuprofen, this compound was completely oxidized under air and oxygen supply. Finally, naproxen was oxidized in the range of 77 up to 99% under both aeration conditions. These findings demonstrate that the oxidative capability of this microorganism for the anti-inflammatory drugs is not restricted to an oxygen environment, as generally accepted, since the fungal reactor was able to remove these compounds under aerated and oxygenated conditions. This result is very interesting in terms of developing viable reactors for the oxidation of target compounds as the cost of aeration can be significantly reduced.     

Visualization of layers lining the lung of the South American lungfish (Lepidosiren paradoxa) and a comparison with the frog and rat.

Comarisons have been made of the structure of layers lining the lungs of lungfish, frog and rat using material fixed by perfusion of the pulmonary circulation of physiological pressures and at normal air pressures within the lung. The lining consists of a thin densely osmiophilic surface layer which covers a much thicker hypophase of generally floccular appearance. Tubular myelin, present in the frog and rat lung lining, was not observed in the layers lining the lung of Lepidosiren.     

The distribution and function of mucous cells and their secretions in the alimentary tract of Arrhamphus sclerolepis krefftii

The mucosa of the mouth, pharynx, oesophagus and rectum of Arrhamphus sclerolepis krefftii contain saccular mucous cells and the lining of the intestinal mucosa contains goblet mucous cells. Saccular mucous cells in the buccal epithelium are present in relatively low densities and contain acidic and neutral glycoprotein-secreting cells in an approximately 1:1 ratio. The saccular mucous cells in the mucosa of the pharynx, oesophagus and rectum are abundant and contain acidic glycoprotein which consists principally of sialomucin with traces of sulphomucin distributed around the periphery of the mucous vacuoles. Goblet cells in the intestinal mucosa contain neutral glycoprotein. Mechanically digested plant material within the lumen of the gut is bound by a sheath of acidic glycoprotein which is in contact with the intestinal mucosa. From these observations and with information on the known properties of acidic glycoproteins, a novel mechanism for the involvement of mucus in the extraction of nutrients from plant material mechanically digested by fish is proposed.     

A Feasibility Study on Pellet Coating Using a High-Speed Quasi-continuous Coater

Pellet coating is traditionally carried out using the Wurster coater. This study investigated the feasibility of pellet coating in a newly developed coater built with a unique airflow system, the Supercell™ coater (GEA Pharma Systems, UK). A full factorial design study was carried out to evaluate the influences of the spray rate of the coating dispersion, batch size of the pellet load, pellet size fraction and plenum pressure of the fluidizing air on the color coating of pellets in the Supercell™ coater. Results showed that pellets could be successfully coated using the Supercell™ coater. Higher plenum pressures and lower spray rates were found to minimize pellet agglomeration during coating. Although coating efficiencies were comparable amongst the different pellet size fractions, larger batch sizes of pellets were coated with higher efficiencies. Process optimization was carried out for each pellet size fraction and a large batch size (120 g) in combination with a high plenum pressure (1,500 mm WC) were deemed optimal. Optimal spray rates differed according to pellet size fraction and a lower spray rate was required for smaller pellets. Pellet flow patterns observed during coating were dependent on the pressure drop across the fluidized load. A ‘swirling’ pellet flow pattern was generally observed at coating conditions which led to optimal outcomes.KEY WORDS: fluid bed, fluidization, pellet coating, pellet flow patterns, pressure drop, process optimization, Supercell™ coater     

Cytokeratin patterns of human oral epithelia: Differences in cytokeratin synthesis in gingival epithelium and the adjacent alveolar mucosa

Human oral mucosa includes various epithelia that are commonly classified as lining, masticatory, and specialized epithelia. Although adjacent tissues, the gingiva and alveolar mucosa represent two different types of epithelia: the gingiva is cornified and exhibits high rate ridges, whereas the mucosa does not normally cornify and exhibits a relatively smooth-contoured borderline between the epithelium and the underlying connective tissue. We examined the cytokeratin patterns of both epithelia using one- and two-dimensional gel electrophoresis. The gingiva expresses a great complexity of cytokeratins, including significant amounts of components nos. 1, 2, 5, 6, 10, 11, 13, 14, 16, and 17, as well as traces of cytokeratins nos. 4 and 15, i.e., a pattern similar to those of vaginal mucosa and epidermis containing proliferative keratinocytes. In contrast, the alveolar mucosa contains only two major cytokeratins, i.e., nos. 4 and 13, together with two minor amounts of cytokeratins nos. 5, 6, 14, and 17, thus resembling the patterns of certain other stratified, noncornified epithelia, such as the esophagus. Immunofluorescence microscopy using monoclonal antibodies to cytokeratins nos. 4 and 13 revealed the presence of these proteins in the suprabasal layers of alveolar mucosa, whereas in the gingiva, only certain small, suprabasal clusters of cells appeared to contain these cytokeratins. The cytoskeletal differences between gingival and alveolar mucosa are discussed in relation to the differences in their morphology and function, and with respect to pathological processes characteristic of these epithelia.     

Nasal reconstruction with a forehead flap in children younger than 10 years of age

Nasal reconstruction has been analyzed extensively in adults but not in children. The purpose of this article is to review the authors' experience with the forehead flap for nasal reconstruction in 10 children under the age of 10 during a 10-year period. Outcomes were assessed by an objective grading system for cosmetic surgical results. Subjective criteria were also applied by an assistant surgeon and by the patients' relatives. Appropriate results were obtained by the following principles: (1) A modified approach that considers three subunits consisting of the dorsum, tip, and ala was used; (2) a forehead flap is the best option for an entire subunit or a full-thickness defect repair; (3) the forehead flap design should be paramedian, oblique, and opposite to the major defect to avoid the hairline and allow better caudal advancement; (4) ear or costal cartilages are good options for structural support (the septum is a nasal growth center that should not be touched); (5) infundibular undermining of vestibular mucosa, turnover flaps, and skin grafts are good options for internal lining; (6) reconstruction is a three-stage procedure (an intermediate operation is added to thin the flap and perform secondary revisions for lining and support); (7) reconstruction should be completed before the child is school aged, to achieve good aesthetic results immediately and avoid psychosocial repercussions; and (8) the reconstructed nose, with skin, lining, and support, will grow with the child (no final surgery should be planned at the age of 18, other than revisions of late complications).     

Rat colonic mucosal cell sialic acid metabolism in azoxymethane-induced tumours

Colonic tissue was examined from normal (control) rats and azoxymethane- (carcinogen-) treated animals. Tumour-bearing colons from azoxymethane-treated rats were divided into malignant and non-malignant areas. Mucosal cells were prepared from the three types of colonic tissue and then examined for DNA and protein content and for the activities of ten enzymes involved in sialic acid metabolism. Enzyme activities were related to either the protein or the DNA content of fractions. The DNA content of cell homogenates was significantly different between tumour and non-malignant tissue and between both these tissues and normal mucosa. The protein content of the 100000 X g membrane pellet and supernatant fraction did not vary significantly between normal and non-malignant material but both these tissues differed significantly from tumour tissue. Significant variation between normal control and tumour tissue was detected at all levels of sialic acid metabolism, including N-acetylhexosamine interconversion and phosphorylation, sialic acid formation and activation, CMP-NeuAc breakdown and transfer and sialic acid release from glycoconjugates. The results indicate that major changes at all levels of sialic acid metabolism are associated with malignancy in rat colonic mucosa. Some of these changes are apparent in non-malignant mucosa and may reflect a pre-malignant state.     

The fine structure of the parabronchi and the gas exchange area of the Adelie penguin lung

The parabronchi of the Adelie penguin are endowed with wide atria forming pockets between a loose meshwork of bundles of smooth muscle cells lining the parabronchial lumen. The atrial epithelium is of variable thickness and bears numerous microvilli, which are overlain by/or embedded in sheets or whorls of lamellar material ("trilaminar substance", diameter of one lamella 8 ..10 nm) forming layers of very variable thickness. The cells contain either stacks or whorls of this material or roundish lamellated bodies, and are interconnected by desmosomal contacts as well as what presumably represent tight junctions. Underneath the epithelium and within the bundles of muscle cells regularly nerve fibres have been found. The diameter of the morphological air/blood barrier is about 165...210 nm in thin areas, excluding a 12...20 nm thick layer covering the luminal plasma membrane of the air capillary epithelium. The blood capillary endothelium ordinarily is markedly thicker (40...250 nm) than the air capillary epithelium (17...25 nm). The basal lamina between endo- and epithelium is a uniform structure measuring about 95...105 nm. The endothelial cells are interconnected by desmosomal and probably tight junctions.     

Peripheral projections of nervus terminalis LHRH-containing neurons in the tiger salamander,Ambystoma tigrinum

The peripheral projections of the nervus terminalis (NT) have been difficult to examine due to the weak immunoreactivity of the processes to various antibodies. We performed two experimental manipulations in the tiger salamander in an attempt to increase the luteinizing hormone-releasing hormone-immunoreactive (LHRH-ir) labelling in the peripheral processes of the NT: 1) the NT was sectioned centrally, or 2) a 100 mg melatonin pellet was embedded subcutaneously for 3 days prior to sacriffice. Following these manipulations, animals were sacrifficed and tissue was processed with standard immunocytochemical techniques for the analysis of the distribution of LHRH-ir processes. In the nasal cavity, LHRH-ir fibers were observed projecting 1) into the rostral olfactory epithelium, 2) to Bowman's glands in the lamina propria of the rostromedial olfactory mucosa and ventrolateral mucosa between the main nasal cavity and Jacobson's organ, 3) into the naris constrictor muscle, and 4) along the palatine nerves and ganglia. These lesion and hormone manipulations have enabled the detection of peripheral projections of the NT not observed previously with immunocytochemical procedures alone. The wide distribution of LHRH-ir NT processes in the nasal cavity and cranium suggests that this nerve may influence many different cranial structures during appropriate pheromonal or neuroendocrine events.     

Temperature effect on the ciliary beat frequency of human nasal and tracheal ciliated cells.

Even though all human respiratory cilia are similar in structure, they experience a wide range of temperatures between the initial part of the nasal fossae which behave as heat exchangers and the inferior part of the trachea, particularly when we inhale exceedingly cold or hot air. The ciliary beat frequency of ciliated cells from human nasal mucosa and from bronchial mucosa averages 8 Hz when measured at room temperature. In the present study we compared the ciliary beat frequency of human cells from nasal and tracheal mucosa brushings at different temperatures from 5 degrees C to 50 degrees C using two different techniques, ex vivo and in vitro: ex vivo in culture medium less than 24 h after sampling and in vitro after demembranation and reactivation according to a standard procedure developed in our laboratory. Measuring the ATP-reactivated ciliary beat frequency allowed us to check the thermal parameters of the dynein ATPase and all the axonemal machinery. No significant difference in frequency was observed between nasal fossae cilia and tracheal cilia when comparing extreme temperatures in both experimental procedures.