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BACKGROUND: Low airway surface pH is associated with many airway diseases, impairs antimicrobial host defense, and worsens airway inflammation. Inhaled Optate is designed to safely raise airway surface pH and is well tolerated in humans. Raising intracellular pH partially prevents activation of SARS-CoV-2 in primary normal human airway epithelial (NHAE) cells, decreasing viral replication by several mechanisms. METHODS: We grew primary NHAE cells from healthy subjects, infected them with SARS-CoV-2 (isolate USA-WA1/2020), and used clinical Optate at concentrations used in humans in vivo to determine whether Optate would prevent viral infection and replication. Cells were pretreated with Optate or placebo prior to infection (multiplicity of infection = 1), and viral replication was determined with plaque assay and nucleocapsid (N) protein levels. Healthy human subjects also inhaled Optate as part of a Phase 2a safety trial. RESULTS: Optate almost completely prevented viral replication at each time point between 24 h and 120 h, relative to placebo, on both plaque assay and N protein expression (P < .001). Mechanistically, Optate inhibited expression of major endosomal trafficking genes and raised NHAE intracellular pH. Optate had no effect on NHAE cell viability at any time point. Inhaled Optate was well tolerated in 10 normal subjects, with no change in lung function, vital signs, or oxygenation. CONCLUSIONS: Inhaled Optate may be well suited for a clinical trial in patients with pulmonary SARS-CoV-2 infection. However, it is vitally important for patient safety that formulations designed for inhalation with regard to pH, isotonicity, and osmolality be used. An inhalational treatment that safely prevents SARS-CoV-2 viral replication could be helpful for treating patients with pulmonary SARS-CoV-2 infection.

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 infection, has led to a pandemic of acute respiratory illness. Pharmacologic treatments for COVID-19 have included treatments that target infection prevention, prevention of viral replication, reduce inflammation, and manage symptoms of respiratory failure caused by the disease. This is a review of key pharmacologic treatments for COVID-19 based on peer-reviewed articles from 2020.

Despite early diagnosis of cystic fibrosis (CF) through newborn screening, a substantial proportion of infants and young children with CF still demonstrate physiologic and structural evidence of lung disease progression, such as obstructive airway disease and bronchiectasis. The growing availability of highly effective CF transmembrane conductance regulatory modulator therapy to the vast majority of people with CF has led to the potential to alter the natural history of CF lung disease, but to assess the full impact of these therapies on CF lung disease and to help guide treatment, sensitive measures of early and mild disease are needed. Chest imaging using computed tomography or magnetic resonance imaging is one approach, but technologic barriers and/or concern about exposure to ionizing radiation may limit its use. However, advances in physiologic measurement techniques and exhaled breath analysis offer another option for assessment of CF lung disease.

Pneumonia is a significant risk for critically ill, mechanically ventilated (CIMV) patients. Diagnosis of pneumonia generally requires a combination of clinician-guided diagnoses and clinical scoring systems. Exhaled breath condensate (EBC) can be safely collected non-invasively from CIMV patients. Hundreds of biomarkers in EBC are associated with acute disease states, including pneumonia. We evaluated cytokines in EBC from CIMV patients and hypothesized that these biomarkers would correlate with disease severity in pneumonia, sepsis, and death. EBC IL-2 levels were associated with chest radiograph severity scores (odds ratio = 1.68; 95% confidence interval = 1.09–2.60; P = 0.02). EBC TNF-α levels were also associated with pneumonia (odds ratio = 3.20; 95% confidence interval = 1.19–8.65; P = 0.02). The techniques and results from this study may be useful for all mechanically ventilated patients.

BACKGROUND: Intravenous formulations of epoprostenol are frequently delivered via nebulizer to treat pulmonary hypertension in acutely ill patients. Although their efficacy as pulmonary vasodilators has been shown to be comparable to inhaled nitric oxide, the local effects of these formulations within the airways have not been determined. We hypothesized that the alkaline diluents of these compounds would lead to increased airway epithelial cell death and ciliary cessation. METHODS: Human bronchial epithelial cells were exposed to epoprostenol in glycine and arginine diluents or control fluid. Ciliary beat frequency, lactate dehydrogenase, and total RNA levels were measured before and after exposure. Results were compared between exposure and control groups. RESULTS: Ciliary beat frequency ceased immediately after exposure to epoprostenol with both diluents. Lactate dehydrogenase levels increased by 200% after exposure to epoprostenol and glycine diluent (P = .002). Total RNA levels were undetectable after exposure to epoprostenol and arginine, indicating complete cell death and lysis (P = .015). Ciliary beat frequency ceased after 30 s of exposure to epoprostenol and glycine (P = .008). There was no difference between cells exposed to epoprostenol and those exposed only to diluent. CONCLUSIONS: Exposure to intravenous formulations of epoprostenol in glycine and arginine caused increased cell death and ciliary cessation in bronchial epithelial cells. These findings suggest that undesired local effects may occur when these compounds are delivered as inhaled aerosols to patients.

Asthma is an obstructive airway disease affecting children and adults throughout the world. It is a heterogeneous disease with a variety of causes and treatments. Research in the diagnosis, treatment, and management of asthma is ongoing, and there were > 8,000 publications on asthma in 2019. This paper reviews several research articles about asthma from 2019 that are most relevant for practicing respiratory therapists caring for patients with asthma.

Exhaled breath condensate (EBC) is a promising source of biomarkers of lung disease. EBC research and utility has increased substantially over the past 2 decades. This review summarizes many of the factors regarding the composition of EBC, its collection, and analysis for the utility of both clinicians and researchers.

Pulmonary hypertension is a life-threatening condition that affects people of all ages that can occur as an idiopathic disorder at birth or as part of a variety of cardiovascular and infectious disorders. It is commonly treated with inhaled pulmonary vasodilators such as nitric oxide and less frequently using formulations and analogs of prostacyclin. To minimize systemic effects and preserve pulmonary vasodilation, vasodilators are often administered directly into the airway. Nitric oxide is the only USA Food and Drug Administration-approved inhaled pulmonary vasodilator that can be used during mechanical ventilation. Over the past two decades, interest has grown in the use of aerosolized prostacyclin and prostacyclin analogs for the treatment of pulmonary hypertension during mechanical ventilation. Clinicians who administer inhaled prostacyclin may not have a clear understanding of its risks because of the lack of data from large clinical trials examining safety and efficacy; moreover, its safe use remains poorly documented. The off-label use of drugs is legitimate, but prescribers must recognize the potential complications and liability in doing so. This manuscript aims to address potential problems related to the aerosol administration of pulmonary vasodilators in the mechanically ventilated neonatal patient.

Mechanical ventilation is frequently used in pediatric patients to ensure adequate gas exchange, ameliorate respiratory distress, and enable resolution of pulmonary or other disorders. However, a number of important challenges remain in the pediatric population because there is a paucity of large-scale randomized controlled trials to generate data and inform clinical practice. This review summarizes a number of discoveries and advances that have been made in pediatric mechanical ventilation from June 2017 to December 2018.

The mechanisms by which transepithelial pressure changes observed during exercise and airway clearance can benefit lung health are challenging to study. Here, we have studied 117 mature, fully ciliated airway epithelial cell filters grown at air-liquid interface grown from 10 cystic fibrosis (CF) and 19 control subjects. These were exposed to cyclic increases in apical air pressure of 15 cmH2O for varying times. We measured the effect on proteins relevant to lung health, with a focus on the CF transmembrane regulator (CFTR). Immunoflourescence and immunoblot data were concordant in demonstrating that air pressure increased F508Del CFTR expression and maturation. This effect was in part dependent on the presence of cilia, on Ca2+ influx, and on formation of nitrogen oxides. These data provide a mechanosensory mechanism by which changes in luminal air pressure, like those observed during exercise and airway clearance, can affect epithelial protein expression and benefit patients with diseases of the airways.

A number of clinical scoring systems for asthma management have been described in the literature over the last four decades.[1][1] These systems are largely used to index severity of disease, quantify changes in disease status, and predict outcomes. Resulting scores can then be used to triage

BACKGROUND: Tissue factor (TF) canonically functions as the initiator of the coagulation cascade. TF levels are increased in inflamed airways and seem to be important for tumor growth and metastasis. We hypothesized that airway epithelia release TF as part of a wound repair program. OBJECTIVES: The goal of this study was to evaluate whether airway epithelia release TF in response to pro-inflammatory stimuli and to investigate roles of TF in cell growth and repair. METHODS: Airway epithelial cells were exposed to 10 μg/mL of lipopolysaccharide or 1 ng/mL of transforming growth factor β (TGF-β). TF and TGF-β messenger RNA and protein were measured in cell lysate and culture media, respectively. Signaling pathways were evaluated by using selective agonists and inhibitors. Airway epithelia were mechanically injured in the presence of TF and tissue factor pathway inhibitor to investigate their roles in wound repair. RESULTS: TF protein levels increased in cell media after exposure to lipopolysaccharide (P < .01) but only in growing cells, and this action was blocked when exposed to an extracellular signal-regulated kinase inhibitor or a “small” worm phenotype and mothers against Decapentaplegic inhibitor. TF protein also increased in the presence of TGF-β (P < .05). Exposure to TF pathway inhibitor decreased the rate of cell growth by 60% (P < .05), and exposure to TF increased the rate of airway healing after injury by 19% (P < .05). CONCLUSIONS: Growing airway epithelia release TF when exposed to lipopolysaccharide or TGF-β. TF reduces wound-healing time in airway epithelia and therefore may be important to airway recovery after injury.

Exhaled breath is a robust matrix of biomarkers divided between three fractions – gaseous breath, volatile breath, and breath condensate. Breath is collected non-invasively through bags (for gaseous breath), cold condensation chambers (breath condensate), and adsorbent traps (volatile breath). Due to the incredibly dilute nature of breath matrices, breath biomarker analysis requires precise analytical techniques, highly sensitive technology and often challenges the limit of detection of even the most advanced assays. Interest and advances in breath collection, analysis, and use have increased in recent years largely due to advances in analytical technology. Approved and validated breath tests are available as tools for researchers and clinicians. Novel development is ongoing. This article reviews the current applications for exhaled breath biomarkers.

To better understand the impact of hypoxia and hyperoxia on neonatal morbidity and mortality, we examined the number of hypoxia and hyperoxia events as well as percentage of time spent outside oxygen saturation targets in relationship to threshold retinopathy of prematurity (tROP) and mortality in preterm infants.Saturation data in 2-second sampling from pulse oximeters was prospectively collected in a single NICU. Average SaO2, low and high saturation events, duration of events, and percentage of time infants spent outside of oxygen saturation range were collected and analyzed continuously during the hospitalization.102 infants1500g or32 weeks gestation were enrolled. There were 125, 112, and 43 hypoxia events/day and 106, 80, and 34 hyperoxia events/day for tROP (N=8), non-survivor (N=16) and non-tROP patients (N=78), respectively. Infants were outside saturation targets for 2:35, 1:38, and 1:03 (hypoxia) and 2:02, 1:25, and 0:38 hours/day (hyperoxia) for tROP, non-survivor and non-tROP, respectively. Time spent outside saturation range (hypoxia, hyperoxia and total time) for the hospital course was higher in tROP (P≤0.006) and non-survivor (P≤0.005) compared with non-tROP patients. The three groups defined themselves in the first 10 days after birth, with regard to duration of hypoxia (P=0.0003), hyperoxia (P=0.0004) and total time outside the targeted saturation range (P=0.0006).Information such as the duration and number of hypoxia and hyperoxia events, as well as total time outside the targeted saturation range, could be factored into assessing clinical interventions and research studies in the prevention, treatment and evaluation of neonatal outcomes.

Background In a patient with positive serum serology for coccidioidomycosis, the differential diagnosis of concurrent pleural effusions can be challenging. We, therefore, sought to clarify the performance characteristics of biochemical, serologic, and nucleic-acid-based testing in an attempt to avoid invasive procedures. The utility of adenosine deaminase (ADA), coccidioidal serology, and polymerase chain reaction (PCR) in the evaluation of pleuropulmonary coccidioidomycosis has not been previously reported. Methods Forty consecutive patients evaluated for pleuropulmonary coccidioidomycosis were included. Demographic data, pleural fluid values, culture results, and clinical diagnoses were obtained from patient chart review. ADA testing was performed by ARUP Laboratories, coccidioidal serologic testing was performed by the University of California-Davis coccidioidomycosis serology laboratory, and PCR testing was performed by the Translational Genomics Research Institute using a previously published methodology. Results Fifteen patients were diagnosed with pleuropulmonary coccidioidomycosis by European Organization for the Research and Treatment of Cancer/Mycoses Study Group criteria. Pleural fluid ADA concentrations were Conclusion Contrary to prior speculation, ADA levels in pleuropulmonary coccidioidomycosis were not elevated in this study. The sensitivity and specificity of coccidioidal serologic testing in nonserum samples remained high, but the clinical usefulness of PCR testing in pleural fluid was disappointing and was comparable to pleural fluid culture.

(1999). Social Reconstructionism for Urban Students. The Clearing House: A Journal of Educational Strategies, Issues and Ideas: Vol. 72, No. 5, pp. 291-294.

“I'm lost,” he sighed to himself. Then, just ahead he noticed the little postal truck idling under a timeless elm. A woman in a blue toboggan—all bundled up against the cold—hustled back to her truck. She'd just made a delivery. Pulling alongside, he rolled down the passenger's window. “Ma'am,” he said, getting her attention. “Can you tell me how to get to Gratitude Street?” She brightened. “Sure. You got a pen?” When he was ready, she spoke, pointing ahead. “So, at the end of this street, go left. That's Family. You'll know Family because every house is wildly different. You'd swear each one had a different Builder. But actually, the same Builder designed every house. It looks like a mess: there's a treehouse, an igloo, a tent, and a Victorian. Every house and every person on Family look so different they seem out of place. But here's the amazing surprise: despite all the differences, every house has some small elements exactly—and I mean exactly—the same as all the others. “Here's how they discovered it,” she said, warming up. “A long time ago, some angry owners—the homeowners association—drew up rules to make the houses look more alike. Some wanted the igloo removed. Move the teepee, said others. A group felt the treehouse was a terrible eyesore. Then, one day the igloo's heater just died. The Inuit went door to door: Do you have a part that looks like this? she asked. Before you know it, everyone on the street was in an uproar! Everyone's house had exactly the same heater! Exactly! House, teepee, igloo, tent: Whatever your house, it had that exact same heater. As they investigated their homes, they noticed other things were also exact copies. They realized that even with their differences, many things were the same. Nowadays, tourist vans go up and down Family, telling how two houses can be very different but in some ways are still just like each other. The Igloo's Heater is their favorite story. “It's a remarkable place,” she said, wistfully. She refocused. “Sorry, I do get off track. Back to your directions. Go 10 blocks on Family and then turn left onto Can't Do It Alone. Pay attention here or you'll get stuck. Whatever the time of day, people are doing things for others. Somebody's always on a ladder washing a neighbor's windows, or baking a shut-in a loaf of bread or chopping them firewood. Everyone is always helping somebody. Funniest thing, too. Once you're on Can't Do It Alone, you may end up staying! “Take Can't Do It Alone 1 mile. You turn right onto Unexpected just after the railroad tracks. Now, Unexpected seems kind of scary. Some houses are terribly beat up. You'll see folks just hanging out, lurking. Shady characters, you'd think. Lock your doors and windows, be respectful, and have courage. But, the thing about Unexpected is that just when you think the folks around there are all one thing, they aren't! “One time, a fella's car broke down on Unexpected in the worst place possible. He saw a man walking toward him. The man wore a big, long coat, the hood pulled up over his head. The traveler's heart started racing. The figure kept coming, determined. The stranded fella was filled with dread. Then, an insistent knock on his window. Then another, unrelenting. Finally, summoning all his courage, he barely cracked his window, hoping this crazy person couldn't get in.” The postal lady paused dramatically. “The hood came off the top of a head—just a little—revealing a grizzled Old Man. He spoke in a gruff but reassuring voice, ‘Stay out here any longer and you're going to catch your death of cold. Come on in, let's get you warmed up and on your way.’” Now, remember that. When you cross the tracks, Unexpected is just beyond. Unexpected can be scary: unfamiliar and unknown things usually are. But, trust me, the folks and experiences on Unexpected are often just what you need, just when you need it.” “After Unexpected, go about 13 blocks. Life is on your right. Turn there. Now, sometimes you think this Life ain't going to ever end. So far, this trip's had lots of surprises: so many twists and turns you feel utterly lost. Now, though, it seems every house is exactly the same. Same trees. Same hedges. Same roofs. You think, ‘Get me out of here! I don't want this. It's the same thing all the time.’ Will I ever get where I'm going? you wonder. I'm bored. You gotta look harder when you think like that. Trust me, I know. There are lots of little differences all along the way, small reminders to look and listen. Seriously. Keep your eyes open. Look real hard. Don't focus on the sameness. Anticipate surprise. Train your eyes to spot details you usually ignore. Believe me, that's the only way to get through Life. Don't give up, either. As soon as you think, That's it. I'm done. I can't take it anymore, you come up to a big Hill. It's really tough to get up that Hill. Just keep going. Eventually, at the very top, there's a Park. “When you get to the Park, take a break. Look around. It's the highest point in this here part of the world. It's so high, it's hard to catch your breath. But, let your senses steep in the beauty of your surroundings. The air is clear and crisp. The only sounds are birds, leaves rustling, and tree branches soothing one another. Soak it in! Trust me, every day after that, you're going to try to remember just how it felt. So, take your time. Make a picture in your mind. “Oh,” she paused. “When you make it up the Hill, it's tradition to leave a little reminder you were there. Maybe it's a special rock in a hidden place. Or, a paper tucked into a tree's hollow. Or, an initial in the dirt or sand. If you have time, do something like that, okay? From there on, you coast gently downhill until you intersect with the most beautiful spot there ever was. If you've followed my directions, you can't miss it. Right there is Gratitude.” With that, she bid farewell. “More holiday deliveries,” she said. What happened to the Lost Man who asked for directions? No one's quite certain. Once you've started following these directions, it's for sure you'll end up at Gratitude. But, it's unknown how many stops you'll make along the way.

We searched MEDLINE, CINAHL, and Cochrane Library database for articles published between January 1990 and December 2012. The update of this clinical practice guideline is based on 237 clinical trials, 54 reviews, and 23 meta-analyses on blood gas analysis (BGA) and hemoximetry. The following recommendations are made following the Grading of Recommendations Assessment, Development, and Evaluation scoring system. BGA and hemoximetry are recommended for evaluating a patient's ventilatory, acid-base, and/or oxygenation status. BGA and hemoximetry are suggested for evaluating a patient's response to therapeutic interventions. BGA and hemoximetry are recommended for monitoring severity and progression of documented cardiopulmonary disease processes. Hemoximetry is recommended to determine the impact of dyshemoglobins on oxygenation. Capillary BGA is not recommended to determine oxygenation status. Central venous BGA and hemoximetry are suggested to determine oxygen consumption in the setting of early goal-directed therapies. For the assessment of oxygenation, a peripheral venous P(O2) is not recommended as a substitute for an arterial blood measurement (P(aO2)). It is not recommended to use venous P(CO2) and pH as a substitute for arterial blood measurement of P(aCO2) and pH. It is suggested that hemoximetry is used in the detection and evaluation of shunts during diagnostic cardiac catheterization.

Depression is highly prevalent in patients with cardiovascular disease, but questions about the effectiveness of screening and intervention remain unanswered. To evaluate the effects of proactive intervention at an acute-care heart and vascular hospital, patients who reported depressive symptoms on admission were randomized to an active, counseling-based depression intervention plus standard care (referral to a primary or psychiatric care physician) or to standard care alone. Despite early termination of patient enrollment because of lower-than-expected recruitment rates, the project had a positive impact. By involving and educating staff, the investigators raised awareness and improved the process of identifying and helping depressed patients. The lessons in study design and execution gained from this experience will help ensure success in future studies of this condition.

BACKGROUND: Airway acidification plays a role in disorders of the pulmonary tract. We hypothesized that the inhalation of alkalinized glycine buffer would measurably alkalinize the airways without compromising lung function or causing adverse events. We evaluated the safety of an inhaled alkaline glycine buffer in both healthy subjects and in subjects with stable obstructive airway disease. METHODS: This work includes 2 open-label safety studies. The healthy controls were part of a phase 1 safety study of multiple inhalations of low-dose alkaline glycine buffer; nebulized saline was used as a comparator in 8 of the healthy controls. Subsequently, a phase 2 study in subjects with stable obstructive airway disease was completed using a single nebulized higher-dose strategy of the alkaline inhalation. We studied 20 non-smoking adults (10 healthy controls and 10 subjects with obstructive airway disease), both at baseline and after inhalation of alkaline buffer. We used spirometry and vital signs as markers of clinical safety. We used changes in fraction of exhaled nitric oxide (NO) and exhaled breath condensate (EBC) pH as surrogate markers of airway pH modification. RESULTS: Alkaline glycine inhalation was tolerated by all subjects in both studies, with no adverse effects on spirometric parameters or vital signs. Airway alkalinization was confirmed by a median increase in EBC pH of 0.235 pH units (IQR 0.56–0.03, P = .03) in subjects after inhalation of the higher-dose alkaline buffer (2.5 mL of 100 mmol/L glycine). CONCLUSIONS: Alkalinization of airway lining fluid is accomplished with inhalation of alkaline glycine buffer and causes no adverse effects on pulmonary function or vital signs.

Exhaled breath condensate (EBC) pH serves as a surrogate marker of airway lining fluid (ALF) pH and can be used to evaluate airway acidification (AA). AA is known to be present in acute respiratory distress syndrome (ARDS) and can be evaluated via continuous EBC pH measurement during mechanical ventilation. Lung recruitment maneuvers (LRMs) are utilized in the treatment of ARDS, however, their impact on EBC pH has never been explored. Here we described the acute effects of two commonly used LRMs on EBC pH. In a prospective, non-randomized, serial exposure study, 10 intubated pediatric subjects with acute respiratory distress syndrome sequentially underwent: a period of baseline ventilation, sustained inflation (SI) maneuver of 40 cm H2O for 40 s, open lung ventilation, staircase recruitment strategy (SRS) (which involves a systematic ramping of plateau pressures in 5 cm H2O increments, starting at 30 cm H2O), and PEEP titration. Maximum lung recruitment during the SRS is defined as a PaO2 + PaCO2 of 400 mmHg. Following lung recruitment, PEEP titration was conducted from 20 cm H2O in 2 cm H2O decrements until a PaO2 + PaCO2 was 380 and then increased by 2 cm H2O. EBC pH, arterial blood gases, lung mechanics, hemodynamics, and function residual capacity were obtained following each phase of the LRM and observational period. Seven out of 10 patients were able to reach maximum lung recruitment. Baseline EBC pH (6.38 ± 0.37) did not correlate with disease severity defined by PaO2/FiO2 ratio or oxygenation index (OI). Average EBC pH differed between phases and decreased after LRM (p = 0.001). EBC pH is affected by LRMs. EBC acidification following LRMs may represent a washout effect of opening acidic lung units and ventilating them or acute AA resulting from LRM.

The relevance of allergic sensitization, as judged by titers of serum IgE antibodies, to the risk of an asthma exacerbation caused by rhinovirus is unclear.We sought to examine the prevalence of rhinovirus infections in relation to the atopic status of children treated for wheezing in Costa Rica, a country with an increased asthma burden.The children enrolled (n= 287) were 7 through 12 years old. They included 96 with acute wheezing, 65 with stable asthma, and 126 nonasthmatic control subjects. PCR methods, including gene sequencing to identify rhinovirus strains, were used to identify viral pathogens in nasal washes. Results were examined in relation to wheezing, IgE, allergen-specific IgE antibody, and fraction of exhaled nitric oxide levels.Sixty-four percent of wheezing children compared with 13% of children with stable asthma and 13% of nonasthmatic control subjects had positive test results for rhinovirus (P.001 for both comparisons). Among wheezing subjects, 75% of the rhinoviruses detected were group C strains. High titers of IgE antibodies to dust mite allergen (especially Dermatophagoides species) were common and correlated significantly with total IgE and fraction of exhaled nitric oxide levels. The greatest risk for wheezing was observed among children with titers of IgE antibodies to dust mite of 17.5 IU/mL or greater who tested positive for rhinovirus (odds ratio for wheezing, 31.5; 95% CI, 8.3-108; P.001).High titers of IgE antibody to dust mite allergen were common and significantly increased the risk for acute wheezing provoked by rhinovirus among asthmatic children.

Teacher growth is an on-going, develop mental process, beginning early in teacher training programs and continu ing throughout a teacher's career. Ac cording to the authors, there are four phases to full professional development. In phase one preservice teachers are given time for focused observation and for understanding different classroom settings and student needs. During stu dent teaching, the second phase, oppor tunities are provided for the application and demonstration of teaching skills, with specific skill emphases being agreed upon by evaluators and student teachers. During phase three provisional teachers receive continuing instruction as a result of need areas identified by su pervisors and master teachers. The final phase of this developmental process en ables practicing teachers to enhance their instructional abilities, refine their pedagogical skills and act as mentors to beginning teachers. Davis and Zaret out line salient aspects of each phase and describe the competencies that should serve as a foundation for a development al model.