By V. Grubuz. Wentworth Institute of Technology.
The technique is also the adoptive (passive) transfer of autoantigen-specifc T cell useful to obtain large amounts of antibodies from the plasma hybridomas in mice can induce autoimmune diseases 20mg tadalis sx with visa. Nick translation signifes the Goodpasture syndrome buy tadalis sx 20 mg online, hyperviscosity syndrome order tadalis sx with paypal, post- movement of a nick, i. It also interacts with polysaccharides, permits the host bacterial cell to resist antibiotics and pro- proteins, and glycosaminoglycans. Plasmid replication stain that identifes increased mitoses and shows greater sen- is independent of the bacterial chromosome. Gel electrophoresis is used with their been widely used to demonstrate plasma cells and lympho- separation. Also called For example, following TdT labeling, biotinylated nucle- hemapharesis. Conditioning of a donor with cytokines to mobilize hematopoietic stem Transduction is the use of a virus to transfer genes, such as cells from the bone marrow into the peripheral blood may the use of a bacteriophage to convey genes from one bacterial be employed to enrich the donor leukocyte preparation for cell to another one. It cies receiving it within a specifed period of time following is equivalent to the Y chromosome’s testis-determining gene. Varying quantities of antitoxin are com- mine the affnity abundance, binding constants, and binding bined with a constant quantity of toxin in vitro. The gel shift assay is are placed in a 44 to 46°C water bath and are observed performed by annealing two labeled oligonucleotides that often. The test is read by noting the tube where foccula- contain the test binding sequence, then incubating the duplex tion occurs frst. The mixture is then separated on a antitoxin has neutralized the homologous toxin. Duplexes that are bound this assay is based on antigenicity of the toxin with which by protein migrate more slowly than unbound duplexes and the antitoxin combines, in contrast to toxicity. Therefore, it appear as bands that are shifted relative to the bands from the is a measure of combining power and provides an indirect unbound duplexes. Also called gel mobility shift assay or gel idea of toxicity only insofar as toxicity and antigenicity are shift assay or gel retardation or band shift assay. Since the two are not always closely correlated, this method is less reliable than the in vivo tech- Zygosity refers to characterization of an individual’s hered- nique of Ehrlich that measures the actual toxic effect of the ity traits in terms of gene pairing in the zygote from which toxin and the ability of antitoxin to combat it. The L value, in contrastf are nontranslatable (known as introns) are excised from the to other L values described, must be calculated. The translatable sequences mine the L value for a given toxin, the following formulaf (known as exons) are united to produce a functional gene is used: product. Therefore values are known: (1) antitoxin units per milliliter of antitoxin; the amount of toxin in a milliliter is substituted into the for- (2) milliliter of antitoxin required for most rapid focculation mula together with the known values, which include the Lf with toxin; and (3) milliliter of toxin employed. Although the per milliliter of toxin and the number of milliliters of anti- Ramon focculation test was classically used to determine the toxin held constant. By simple arithmetic, the antitoxin units L value of toxin, it may be carried out in reverse to assay thef per milliliter may then be calculated. In this quantitative pre- antitoxin units in each milliliter of antitoxin which has not been cipitin test, antibody dilutions are varied, but antigen dilu- previously standardized. Varying quantities of toxin of known L value are com-f Stochastic models: Designs characterized by chance events bined with a constant amount of antiserum. Diagnostic Immunohistochemistry 29 Immunohistochemistry is a method to detect antigens in the antibody portion of this complex, which is raised in rab- tissues that employs an enzyme-linked antibody specifc for bits, will be bound to the free antigen-binding site of the antigen. The enzyme degrades a colorless substrate to a col- linking antibody on the sections. Diagnostic mits the formation of a visible product that may be detected pathology services routinely offer approximately 100 anti- with the light microscope. The immu- covered with mounting medium and cover slips, and read noperoxidase technique permits the demonstration of anti- by conventional light microscopy. The disadvantages include the following: noperoxidase reaction that is employed extensively in antigen (1) the demonstration of relatively minute positively staining identifcation in histopathologic specimens, especially in surgi- areas is limited by the resolution of the light microscope; (2) cal pathologic diagnosis. This has proven highly successful for the demon- read by light microscopic observation. Tissue sections preserved in Immunodiagnosis involves the use of antibody assays, paraffn are frst treated with xylene, and after deparaffni- immunocytochemistry, the identifcation of lymphocyte zation they are exposed to a hydrogen peroxide solution that markers, and other techniques to diagnose infectious dis- destroys the endogenous peroxidase activity in tissue. This antigen is expressed by 84% of invasive ductal breast carci- so-called linking antibody will combine with any primary noma and 85 to 90% of colon, pancreatic, gastric, esophageal, rabbit antibody in the tissue. It is added in excess, which lung (non-small cell), ovarian, and endometrial adenocarci- will result in one of its antigen-binding sites remaining free. Lung adeno- formalin resistant, permitting the detection of ovarian cancer carcinoma rarely stains with this antibody. Normal apocrine sweat nal antibody is specifc for a regulatory protein present in glands, eccrine glands (variable), minor salivary glands, smooth muscle and selected other tissues. It interacts with bronchial glands, metaplastic breast epithelium, benign sweat actin, myosin, tropomyosin and calmodulin. It participates in smooth muscle contrac- with greater reliability than nonspecifc stains (e. It may also be positive in malignant myothepi- Antibroad-spectrum cytokeratin is a mouse monoclonal thelioma, pleomorphic adenoma of the salivary glands, and antibody that may be used to identify cells of normal and angiomatoid malignant fbrous histiocytoma. The pankeratin cocktail recognizes was later shown to be present in certain other conditions as most of the acidic and all of the basic cytokeratins, making it well. This antibody binds specifcally to antigens located cervical, bladder, medullarythyroid, and prostatic carcinoma. The antibody is used to qualitatively stain cytok- noma, lymphoproliferative disease, and smokers. In anaplastic tumors, the per- to the level immediately following surgery, this may signify centage of tumor cells showing cytokeratin reactivity may be metastases. Unexpected antigen expression or loss of peptide chain with one variable region at the amino terminus expression may occur, especially in neoplasms. It is detected with a mouse of any staining or its absence must be complemented by mor- monoclonal antibody directed against a complex glycoprotein phological studies and evaluation of proper controls. This reagent may be used to aid in the identifcation of cells Anti-high molecular weight human cytokeratin antibod- of epithelial lineage. The antibody is intended for qualitative ies are mouse monoclonal antibodies that identify keratins of staining in sections of formalin-fxed, paraffn-embedded tis- approximately 66 kDa and 57 kDa in extracts of the stratum sue. The antibody labels squamous, ductal, and other in the plasma membrane and cytoplasmic regions of normal complex epithelia. Unexpected antigen expression or loss of neoplasms and variably with those derived from simple epithe- expression may occur, especially in neoplasms. Consistently positive are squamous cell carcinomas and stromal elements surround heavily stained tissue and/or cells ductal carcinomas, most notably those of the breast, pancreas, which show immunoreactivity. Clinical interpretation of any bile duct, and salivary gland; transitional cell carcinomas of staining or its absence must be complemented by morphologi- the bladder and nasopharynx; and thymomas and epithelioid cal studies and evaluation of proper controls. Antibodies to this molecule melanomas, neural tumors, and neuroendocrine tumors are confrm its presence and reveal the morphological appearance unreactive. Normal tissue stains with this antibody in a fashion consistent with the sites of mesenchymal elements and Cytokeratin (34betaE12), mouse: Anticytokeratin (34beta epithelial basal laminae. This antibody recognizes cytokeratins 1,5,10, and 14 neoplasma, hemangiopericytoma, angiosarcoma, and epithe- that are found in complex epithelia.
Autorotational keratoplasty is sometimes with interference in the ditferentiation of the central cornea suitable tadalis sx 20mg generic. Congenital or postsurgical glau Isotretinoin intake in the first trimester of gestation can coma is a major cause of visual loss in many cases discount 20 mg tadalis sx overnight delivery. Families with a child with isolated bilateral Peters’ for the existence of a clinical syndrome combining Peters’ anomaly should be counseled as to the possible recessive anomaly and other congenital anomalies buy tadalis sx without a prescription. Therefore, primary aphakia is usu drome, but the reported deletions or duplications provide ally accompanied by severe ocular malformations such as starting points to amplify the knowledge regarding genes colobomatous microphthalmia, anterior segment dysgenesis or a group of genes involved in ocular development. There may be associated corneal or anterior segment abnor malities but there are no severe ocular malformations. The opac ities may be relatively flat and reduplicate under the anterior lens capsule or they may assume a pyramidal shape and pro trude into the anterior chamber. Although generally consid ered to be of little visual significance, lenses with anterior polar opacities may opacify with time and may require surgical intervention. As such may be included Familial congenital cornea guttata with anterior polar cataracts. We have the anterior lens epithelium is implicated in the induc recorded a variety of anterior segment malformations in tion of anterior segment development in animal models. These mal In humans, diverse anterior segment conditions such as formations included cornea guttata, posterior embryo Fuchs’ dystrophy, posterior polymorphous dystrophy and toxon, diffuse iris atrophy in a slightly microphthalmic Alport syndrome, where corneal and lens abnormalities eye, aniridia and remnants of the pupillary membrane. Patients with anterior polar cataracts should be monitored carefully for the presence of glaucoma, especially following lens extraction. Note slightly smaller eye and more quently, irregularities in lens contour may occur with typical even surface of the iris on the right. D escription of X linked megalo ciliary processes, breaks of the pars plicata and retinal cornea with identification of the gene locus. Corneal endothelial cell m easurem ent This syndrome is presumed to result from a localized or in m egalocornca. I Pediatr A single patient has also been described with lenticu O phthalm ol Strabismus 1984:21:190. Syndrom e o f m ental retar dation seizures hypotonic cerebral palsy an d m egalocornca reces- dystrophy. Visual im pairm ent and prolonged surivival in a girl w ith M arshall-Smith syndrome. A new association of congenital hydrocephalus, albinism , megalocornca, and retinal colobom a in a syndrom ic child: a clinical and genetic study. Studies o f X-linked recessive ocular albinism o f the Ncttleship-Falls type—with special reference to the association o f megalocornca. Progressive facial hem iatrophy with megalocornea, micropupil and central nebular dystrophy of the cornea. Spontaneous resolution o f prim ary congenital associated with sclcrocornca aniridia and a chrom osom al abnorm al glaucoma. Homozygous nonsense m utation in autosom al dom inant congenital cataract and m icrocornea. Ring derm oid syndrom e: a cataract, ocular anterior segm ent dysgenesis and colobom a. I lum new syndrom e of autosom al-dom inantlv inherited bilateral annular Mol Genet 2002;11:33-42. Dev Biol (15)N chcmical shift assignm ents for the hum an Pitx2 hom codo- 2000;220:424-31. Potential m apping o f corncal somal dom inant vitreoretinochoroidopathy: a degenerative disease derm oids to Xq24-qtcr. Bcr Dcutsch Ophthalmol com bining juvenile cataract with m icrocornea and renal glucosuna. Axenfeld-Rieger syndrome: a theory of m echanism and review of inferior rectus muscle aplasia in 16 Japanese patients. Rieger syndrom e and interstitial 1q26 Willi syndrom e, congenital ectropion uveae with glaucoma, and deletion. Classification ofcorneal endothelial dis the region of the epiderm al growth factor gene on chrom osom e 4. In: Molecular somal dom inant disorder with ocular dental and systemic abnor Genetics of Ocular Diseases. Br J chrom osom e band 1q26 in a m alform ed girl: exclusion of Rieger O phthalm ol 1965;49:530-7. Pcriumbilical skin length nant iris hypoplasia to the region of the Rieger syndrom e locus m easurem ents in the new born. Am J Hum Genet hypertelorism and psychom otor retardation: a dom inantly inher 1997;61:765-8. Jpn J O phthalm ol m utations suggests gene dosage as a m echanism for developmental 1981;25:321-5. Molecular and developm ental m echanism s of anterior bras court d u n chrom osom e 10 associcc a un syndrom e de Rieger segm ent dysgenesis. Peters’ anom aly with congenital m utations cause Alagille syndrom e, a heterogeneous disorder of the aphakia. Acta Ophthalm ol tions in Alagille syndrome: increasing the m utation detection rate. O phthalm ology 1993; corneal opacities and profound psychom otor retardation: a newly 100:1767-74. Arch Ophthalm ol dysgenesis in craniosynostosis syndrom es with a libroblast growth 1986;101:60-4. Ucbcr angeborene Dcfcktbildung der Dcsccmctschen Peters’ anomaly typical facial appearance failure to thrive hydro M embran (A natom ische U ntersuchung eines Falles von ange cephalus and other anomalies: further delineation of the Krause- borener H ornhauttrubung ringform igcr vorderer Syncchic und Kivlin syndrom e. Parvovirus B19 Robinow -likc syndrom e w ith anterior cham ber cleavage anom alies. Familial congenital cornea guttata in association with Am ) H um G enet 2006;79:562-6. Familial congenital cornea guttata with o f C Y PlB l: m utations in a patient with Peters* anomaly. Congenital cataract w ith m icrocornea and dom inant anterior segm ent m alform ations. Br J O phthalm ol Peters anom aly as expressions o f one autosom al dom inant gene. Optical iridectomy for corneal pars plicata associated with colobom a lentis and ocular hyperten opacities in Peters anomaly. Bilateral aniridia Icnticular colobom a ipsilateral rotating penetrating keratoplasty: an early surgical pro and snowflake retinal degeneration. O phthalm ic Surg Lasers cedure to prevent deep irreversible amblyopia in Peters anomaly). I Am Assoc Pediatr Ophthalm ol Strabismus 20U0;4: A m J O phthalm ol 1964;58:10l 1-6.
Histopathologically it reveals numerous small cheap 20 mg tadalis sx overnight delivery, follicle- like structures tadalis sx 20 mg fast delivery, frequently with radially penetrating buy tadalis sx 20 mg mastercard, thick- walled, hyalinized vessels; concentrically arranged small lymphocytes around the follicular structures called “onion skinning” and extensive proliferation of capillaries in the interfollicular areas. The second type of Castleman disease is plasma cell angiofollicular lymph node hyperplasia which comprises 10% of the cases. The mass may consist of multiple matted lymph nodes with histopathologic features Figure 17. A multicentric type of the plasma cell variant of portend development of lymphoma in the future, although it angiofollicular lymph node hyperplasia is more aggressive. Clinical features of plasma cell angiofollicular hyperplasia include Reticulosis: See lymphoma. Their immunoglobulin genes manifest which there is a uniform accumulation of lymphocytes. The architecture of the lymph node is well preserved with distinct cortical B symptoms are symptoms that often occur in lymphoma germinal centers with little or minimal capsular infltration patients. Infammatory cells are detectable between fever, and night sweats often associated with chest pain. It affects the jaws and be found in various locations such as gastrointestinal tract, abdominal viscera. Pseudolymphomas may occur in individuals reveal rearrangement between the c-myc-bearing chromo- who later develop lymphomas. Burkitt lymphoma patients have antibodies Lymphomatosis refers to numerous lymphomas occurring to the Epstein–Barr virus in their blood sera. The disease in different parts of the body, such as those occurring in occurs in geographic regions that are hot and humid and Hodgkin’s disease. It occurs in subjects with acquired immunodefciency and in other immunosuppressed individu- Biclonality: In contrast to uncontrolled proliferation of a als. There is an effective immune response against the lym- single clone of neoplastic cells which is usually associated phoma that may lead to remission. It is licular hyperplasia and loss of the distinct boundary between expressed in tonsils and secondary lymphoid organs, and the mantle zone and the germinal center. Most Burkitt lymphoma cell lines nal centers contain small lymphocytes with diffuse immuno- express the receptor. M y c is an oncogene designated v-myc when isolated from the avian myelocytomatosis retrovirus and designated c-myc when referring to the cellular homologue. The myc genes are activated by overexpression either by upregulation, caused by transcriptional regulatory signal mutations in the frst intron, or by gene amplifcation. When c-myc is in its normal position on chromo- some 8, it remains transcriptionally silent, but when it is translocated, as in Burkitt lymphoma, it may become acti- vated. The protooncogene c-myc is amplifed in early carci- noma of the uterine cervix, lung cancer, and promyelocytic Figure 17. There is a for this purpose to develop long-term B lymphocyte cul- generalized erythroderma, hyperpigmentation, and exfolia- tures. It causes infectious mononucleosis and ing in the epidermis forming Pautrier’s abscesses. Late in the establishes a latent infection of B cells that persists for life disease, T immunoblasts may appear. Epstein–Barr nuclear antigen is a molecule that occurs in B cells before virus-directed protein can be found in nuclei of Sezary cells are T lymphocytes that form E rosettes with infected cells. Thus, it is the earliest evidence of Epstein–Barr sheep red cells and react with anti-T antibodies. Sezary cells virus infection and can be found in patients with conditions from most individuals show a diminished response to plant such as infectious mononucleosis and Burkitt lymphoma. Sezary cells neither produce immature hematopoietic cells express during differentiation. It rep- (Mediterranean lymphoma heavy chain disease): A varied resents a truncated genetic form of c-myb. Whereas the monoclonal protein is Epstein–Barr virus-induced Burkitt lymphoma occurs. Patients experience weight loss, pain in the abdomen, diarrhea, and malabsorption. There is expan- sion of the mesenteric lymphoid tissue and of the proxi- mal small intestine. The infammation induced by these agents is manifested as erythema and swelling at approxi- Bulla formation mately 12 h after contact and is maximal at 24 to 48 h. Blisters Linear IgG and C3 flled with serum, neutrophils, and mononuclear cells form. Langerhans cells in the skin serve as antigen pro- cessing cells where the allergen has penetrated. Sensitization especially in children with a genetic predisposition to lasts for many years and becomes generalized in the skin. These are often accompanied by elevated serum Chemicals become conjugated to skin proteins and serve as IgE levels, which are not proved to produce the skin haptens. Metal dermatitis, such as that caused by blistering skin disease with fuid-flled bullae developing nickel, occurs as a patch that corresponds to the area of con- at fexor surfaces of extremities, groin, axillae, and inferior tact with the metal or jewelry. IgG is deposited in a linear pattern at the lamina skin lesions at points of contact with the skin. The patch test lucida of the dermal–epidermal junction in most (50 to 90%) is used to detect sensitivity to contact allergens. The blisters are titis represents a reaction to urushiols in poison oak or ivy that subepidermal bullae flled with fuid containing fbrin, neu- elicit vesicles and bullae on affected areas. Antigen–antibody– systemic corticosteroids or the application of topical steroid complement interaction and mast cell degranulation release cream to localized areas. Bullous pemphigoid antigen: the principal antigen is a 230-kDa basic glycoprotein produced by keratinocytes in Atopic dermatitis (Figure 17. Autoantibody and complement react with this skin reaction marked by hyperkeratosis and spongiosis antigen to produce bullous pemphigoid skin lesions. Dietary gluten exacerbates the condition and should be avoided to help control it. IgA and C3 granular immune deposits occur along dermal papillae at the dermal–epider- mal junction. Groups of papules, plaques, or vesicles appear in a symmetrical distribution on knees, elbows, buttocks, posterior scalp, neck, and superior back region. Microscopic blisters, which ultimately develop into subepidermal blisters, may develop at the tips of these papillae. The bullae develop on normal appearing skin and rupture another as the bulla develops. The blisters are prominent on both oral and anal geni- by autoantibodies may actually cause the loss of intercellular tal mucous membranes. Immunofuorescence staining reveals IgG, Clq, and onset appearing in middle-aged individuals and tends to be C3 in the intercellular substance between epidermal cells.
The patient’s effort can be “sensed” as a change in pressure or a change in flow in the circuit (flow triggering) order tadalis sx. A setting of greater than 0 makes it too sensitive (meaning the triggered breath from the ventilator will be too frequent) order tadalis sx on line amex. Too negative setting will increase the work of the patient (to generate a negative pressure) to trigger a ventilator breath generic tadalis sx 20mg on-line. It delivers the breath with a decelerating flow pattern that is thought to be less injurious to the lung. Volume Support Volume support is in principle equivalent to pressure support where a “goal” tidal volume is set and machine delivers that volume at variable pressure support, but within the set limits of pressure support. The machine watches the delivered volumes and adjusts the pressure support to meet desired “goal” within limits set. Initial Ventilator Settings One should always have the general idea regarding, what initial ventilatory settings to chose when initiating the ventilation. Normal I:E ratio = 1:2-1:3 • Higher I-times may be needed to improve oxygenation in difficult situations (Inverse ratio ventiation) increasing the risk of air leak. Gas Exchange Related Problems Inadequate oxygenation (hypoxemia) Inadequate ventilation (hypercarbia) Inadequate Oxygenation Important guidelines: 1. Inadequate tidal volume delivery (hypoventilation) will occur with endotracheal tube block, malposition, kink, circuit leak, ventilator malfunction. If volume limited: Increase tidal volume (Vt), Increase frequency (rate) (f) If asthma: Increase expiratory time, may need to decrease ratio achieve an I:E ratio >1:3. Change endotracheal tube if blocked, kinked, malplaced or out, check proper placement 6. Measures to Reduce Barotrauma and Volutrauma: Folowing concepts are being increasingly followed in most pediatric intensive care units. Permissive hypoxemia: PaO2 of 55-65; SaO2 88-90% is acceptable in exchange for limiting FiO2 (<. Patient ventilator dysynchrony:Incoordination between the patient and the ventilator: Patient fights the ventilator!! If patient fighting the ventilator and desaturating: Immediate measures Use Pnemonic: D O P E D—displacement, O—obstruction, P—pneumothorax, E—equipment failure 1. Check tube placement: When in doubt take the endotracheal tube out, start manual ventilation with 100% oxygen. Check arterial blood gas and chest X-ray for worsening lung condition, and for confirming pneumothorax. If no other reason for hypoxemia: increase sedation/muscle relaxation, put back on ventilator. Routine Ventilator Management Protocol Following protocol is commonly followed: 1. Frequent clinical examination for respiratory rate, breath sounds, retractions, color 5. Its use is well established only in acute atlectasis and pediatric lung abscess in children greater than 7 years. This in turn leads to retention of secretions super added bacterial infection and nosocomial pneumonia. These include the upright posture in a person who has obesity, ascites, abdominal surgery, or the 45o angle to decrease the risk of aspiration in a person being enterally fed. A person with unilateral lung disease is to be placed with the affected lung uppermost in order to improve drainage of secretion and also for a better V/Q matching14 (as both perfusion and ventilation will increase in the gravitationally assisted normal lung). Vibration is generally used in neonates to avoid damage to their fragile chest walls. Manual hyperinflation: It is usually performed before and between suctioning to prevent hypoxemia while suctioning. The patient is disconnected from the ventilator and is bagged with a resuscitator bag using slow deep inspiration, inspiratory hold and quick release to enhance expiration. Despite its widespread acceptance for removal of secretions, its superiority over chest physiotherapy has not been proven. Neonates and children with fragile bones such as in rickets and osteogenesis imperfecta can develop rib fractures. Studies however reveal that continuous rotational therapy and kinetic percussion20 decreases pulmonary complications. Studies done in adults show that chest physiotherapy fails to decrease the length of hospitalization, length of fever11 or duration of ventilation. Medical gases have no humidity and bypassing the upper airway as in patients with artificial airway such as endotracheal tube or tracheostomy makes humidification a must. Excessive humidification is also a problem and can decrease mucociliary clearance, cause hyper-hydration and loss of surfactant activity. The appropriate temperature and humidity to be used in ventilated patients has not yet been established. These are to be used only with a high flow system such as that needed during mechanical ventilation. The temperature of the inspired gas has to be monitored in order to avoid over heating and tracheal burns. Heated wire circuit: In an attempt to decrease the rainout associated with heated water humidifier, heated wire circuit is available. Its use can increase dead space and resistance, which may be overcome by increasing pressure support. It can be used safely up to a week32, 34 or until visible liquid contamination occurs. This gets converted to cost saving on disposables, fewer need for breaking the circuit and hence reduction in bacterial contamination. Aerosol Therapy Aerosol is a group of particles suspended in air for a relatively long time. Aerosol therapy is used in order to deliver the drug directly to the site of action, there by minimizing the systemic side effects and improving the efficacy. Aerosol gets deposited through the process of impaction, sedimentation and diffusion. Particles around 2 μm get sedimented due to gravity and still smaller particles undergo diffusion. The latter however has a greater versatility and can be adapted to deliver various drugs. An array of drugs like bronchodilators, steroids, antibiotics, anticholinergics, mucolytics, prostacyclin, etc. The amount of the drug deposited in the lower airway will depend on several factors such as physiochemical properties of the drug,33, 35, 36 the nature of the device, position of the device in the circuit, the nature of the ventilator circuit, ventilatory parameters, humidity and density of the inspired air and on the airway anatomy. The larger size particle can get impacted in the endotracheal tube and in the ventilator circuit. Continuous operation requires the nebulizer to be driven by a pressurized gas source.