Coding for Otolaryngology Office Procedures

This review article provides a summary of current correct coding for in-office surgical procedures. The relevant Current Procedural Terminology codes are covered and tips and guidance provided for their correct use. Also, where applicable, facility versus nonfacility reimbursement policy and the associated implications for physicians practicing in hospital-based clinics are discussed.

MetaMap: an atlas of metatranscriptomic reads in human disease-related RNA-seq data

Background

With the advent of the age of big data in bioinformatics, large volumes of data and high-performance computing power enable researchers to perform re-analyses of publicly available datasets at an unprecedented scale. Ever more studies imply the microbiome in both normal human physiology and a wide range of diseases. RNA sequencing technology (RNA-seq) is commonly used to infer global eukaryotic gene expression patterns under defined conditions, including human disease-related contexts; however, its generic nature also enables the detection of microbial and viral transcripts.

Findings

We developed a bioinformatic pipeline to screen existing human RNA-seq datasets for the presence of microbial and viral reads by re-inspecting the non-human-mapping read fraction. We validated this approach by recapitulating outcomes from six independent, controlled infection experiments of cell line models and compared them with an alternative metatranscriptomic mapping strategy. We then applied the pipeline to close to 150 terabytes of publicly available raw RNA-seq data from  more than 17,000 samples from more than 400 studies relevant to human disease using state-of-the-art high-performance computing systems. The resulting data from this large-scale re-analysis are made available in the presented MetaMap resource.

Conclusions

Our results demonstrate that common human RNA-seq data, including those archived in public repositories, might contain valuable information to correlate microbial and viral detection patterns with diverse diseases. The presented MetaMap database thus provides a rich resource for hypothesis generation toward the role of the microbiome in human disease. Additionally, codes to process new datasets and perform statistical analyses are made available.

The Value of Mentorship

The recent Young Physicians needs assessment survey identified mentorship as the single greatest need for this demographic, which includes physicians under 40 years of age or in their first 8 years of practice after completion of training. Much has been written in textbooks and other journals about mentorship, and as young physicians are certainly not alone in this need, mentorship has become a key focus of future Academy endeavors. Serving as Chair of the Young Physicians Section over the past year has afforded me the opportunity to interact with a variety of dynamic and engaging leaders in our Academy, and herein I provide a synopsis of what these experiences have taught me as well as provide some of the most important pearls that I have picked up along the way.

The Management of Spontaneous Otogenic CSF Leaks: A Presentation of Cases and Review of Literature

Objective The types of otogenic cerebrospinal fluid (CSF) fistulae were previously classified into defects through, adjacent to, or distal to the otic capsule. This article presents cases of the three different types of spontaneous CSF fistulae and reviews pertinent literature. We examine the management of the different types of otogenic CSF leaks with modern audiovestibular testing, imaging, and surgical techniques. Design Case series and review of the literature. Setting Academic tertiary neurotologic referral practice. Participants Four patients identified through a retrospective search. Main outcome measures Resolution of CSF leak and absence of meningitis. Results Surgical intervention was performed on the four cases described in this series; none had a return of CSF otorrhea in the postoperative period or meningitis. Conclusions Otogenic CSF fistulae may lead to life-threatening infection and in congenital forms are typically not diagnosed unless meningitis has occurred. Rapid and proper recognition, work-up, and treatment of such leaks decrease the risk of permanent neurologic sequelae as well as recurrent meningitis.

Using Social Media in Medicine

Program Description:

Social media has moved from an emerging technology to a mainstay of our patients’ lives. The panelists consist of speakers at the forefront of the social media field in otolaryngology in both academic and private arenas. This talk will demonstrate how social media has already been incorporated in the medical marketplace and future applications. We will discuss strategies for how physicians can incorporate this into their academic/private practices. Common pitfalls encountered in assimilating social media into your practice will be described. Additionally, we will discuss the inherent medico-legal risk and ethical considerations associated with these endeavors.

Educational Objectives:

1) Discuss how social media affects medicine today. 2) Describe methods to use social media to help build/maintain your practice in an academic and private arena. 3) Apply the best uses of social media to interact with and educate your patients while being aware of the medico-legal implications.

Avenues to Leadership: Opportunities at Every Level

Program Description:

This miniseminar is designed to help physicians in the Academy find ways to become leaders in their own environments. The panelists will include leaders within national organizations such as the AAO-HNS, ACGME, and ACS, as well as local leaders, including a department chair and residency program director. Emphasis will be placed on career crossroads and how to navigate them. Several of the panelists are women and will comment on experiences unique to female leaders in our field.

Educational Objectives:

1) Recognize individualized ways to become leaders in various environments. 2) Characterize the role of medical leaders in our departments, institutions, clinical specialties, and national organizations. 3) Apply leadership principles to everyday practice.

Pediatric peritonsillar abscess: Quinsy ie versus interval tonsillectomy

PERITONSILLAR ABSCESS

Quinsy versus interval tonsillectomy.

OBJECTIVES STUDY DESIGN

Case series with chart review.

METHODS

We reviewed the records of children treated for peritonsillar abscess between 2007 and 2011 at an academic tertiary pediatric hospital. We identified patients by searching the hospital database for all children treated for the ICD-9 code 475 (peritonsillar abscess). Data points extracted included length of stay, intraoperative blood loss, operative time, and incidence of complications. Statistical analysis was performed to identify significant differences between treatment categories. Children who never received a tonsillectomy (CPT codes 42820/42821/42825/42826) were excluded.

RESULTS

34 children received tonsillectomy for peritonsillar abscess from 2007 to 2011. Of these: 23 received a Quinsy tonsillectomy, and 11 received antibiotics with or without incision and drainage, followed by tonsillectomy a minimum of 2 weeks later. Total hospital days in treatment course was 2.2 days for Quinsy tonsillectomy group and 2.3 days for the interval tonsillectomy group. Estimated blood loss was less than 20 ml for both groups. Operative time was 38 min for Quinsy tonsillectomy and 39 min for interval tonsillectomy. There were no post-tonsillectomy hemorrhages. One patient in the interval tonsillectomy group required readmission for dehydration.

CONCLUSION

There were no significant differences in total hospital days, blood loss, operative time, or post-operative complications between Quinsy tonsillectomy and interval tonsillectomy in the treatment of pediatric peritonsillar abscess.

Airway Management following Pediatric Cardiothoracic Surgery

Objectives

(1) Review airway management in pediatric patients undergoing cardiothoracic surgery (CTS); (2) determine the incidence of airway-related complications of CTS in this population.

Design

Case series with chart review.

Setting

Tertiary care children’s hospital.

Patients

Children undergoing CTS over a 4-year period.

Methods

Patients who underwent CTS at a single, tertiary care, children’s hospital between June 1, 2007, and May 31, 2011, were retrospectively reviewed; those <18 years who had open CTS were included. Statistical analysis examined relationships of intubation duration, complications, and need for tracheotomy while comparing patient characteristics, comorbidities, and types of surgery.

Results

Eight hundred seventy-five primary surgeries in 745 patients met inclusion criteria. Mean postoperative intubation duration was 7.2 days and median 3 days. On univariate analysis, significantly longer postoperative intubation requirements were found in patients younger in age, with congenital comorbidities or prematurity, with preoperative ventilation requirements, and those with early postoperative complications. Multivariate analysis found younger age, presence of congenital comorbidities, preoperative intubation requirements, and early postoperative complications each lengthen ventilation requirements. Four patients developed vocal cord paralysis and 5 developed phrenic nerve palsy. Nineteen patients required tracheotomy.

Conclusions

In this large cohort, CTS in the pediatric population is associated with few long-term or permanent airway-related complications. Patients who are younger in age and those with congenital comorbidities, preoperative ventilation requirements, or early postoperative complications required longer periods of postoperative intubation.

Successful discontinuation of propranolol for infantile hemangiomas of the head and neck at 12 months of age

BACKGROUND

Although propranolol can be an effective primary medical therapy for infantile hemangiomas of the head and neck, the duration of treatment and time to discontinue propranolol is unclear.

OBJECTIVE

The objective of this study is to determine the duration of treatment and age at which propranolol may be successfully discontinued in children with infantile hemangiomas of the head and neck.

METHODS

A review of all patients presenting to a pediatric vascular anomalies clinic from January 2008 to December 2011 was performed. Those with head and neck infantile hemangiomas who completed propranolol therapy were included. Each patient's records were reviewed for demographics, clinical response to propranolol, age at discontinuation of propranolol, and adverse events.

RESULTS

Forty-five patients were included for review (mean age at presentation, 3.5 months) with all demonstrating positive responses. The mean age at discontinuation of propranolol was 11.8 months of age (range, 8-15 months) with a mean treatment duration of 6.5 months (range, 3-11 months). No recurrences were noted over a mean follow-up period of 19.9 months (range, 10-28 months).

CONCLUSION

Discontinuation of propranolol at approximately 12 months of age was found to be appropriate in our study population.

Airway Management following Pediatric Cardiothoracic Surgery

Objective: Little is currently known regarding outcomes in airway management of pediatric patients following cardiothoracic surgery (CTS). This study aims to 1) review airway management in a large cohort of pediatric patients undergoing CTS and 2) determine the incidence of airway related complications of CTS in this population.

Method: All patients who underwent CTS at a single, tertiary care, dedicated children’s hospital between June 1, 2007, and May 31, 2011, were retrospectively reviewed; those <18 years old who had open CTS were included. Statistical analysis examined the relationships of intubation length, tracheotomy, and complications compared to patient characteristics, comorbidities, and type of surgery.

Results: Nine hundred five admissions in 762 patients met inclusion criteria. Mean postoperative intubation duration was 7.2 days (d), and the median was 3 d. Significantly longer postoperative intubation requirements were found in patients <2 years (mean 9.7 d, median 4 d) vs >2 years (mean 2.4 d, median 2 d, P < .001) and those with comorbidities (mean 11.0 d, median 4 d) or history of prematurity (mean 8.8 d, median 4 d) vs those without comorbidity (mean 5.5 d, median 3 d, P < .001). Additionally, preoperative intubation and surgical incision type significantly affected intubation duration. Vocal cord paralysis occurred in 3 patients, and phrenic nerve palsy occurred in 5. Twenty-four patients required tracheotomy. Five patients developed airway stenosis.

Conclusion: After reviewing a large cohort of patients, this study finds CTS in the pediatric population is associated with few long term or permanent airway related complications. Patients with a history of prematurity, medical comorbidity, and/or younger age at the time of surgery require longer periods of postoperative intubation.

Finding Balance in a Surgical Career

Program Description: One of the most common problems many physicians struggle with is maintaining work-life balance. As physicians, we all face extraordinary demands on our time and need to learn how to balance the demands of our careers and family, while also allowing time to cultivate personal interests. Dealing with all of these demands creates stress for both physicians and their families. During this interactive miniseminar, practical techniques and pearls regarding time management and work-life balance will be shared by fellow otolaryngologists. The panel will include both private and academic otolaryngologists who manage busy practices and make substantial contributions to their institutions and specialty societies, while maintaining strong relationships with their friends and families and pursuing interests outside of medicine.

Educational Objectives: 1) Identify obstacles to work-life balance and achieving personal and professional goals. 2) Develop time management and efficient communication skills at work such as how to organize your schedule, control the pace of patient encounters, and trim work flow. 3) Streamline personal errands and chores to maximize time spent with family and interests.

Immediate versus Interval Tonsillectomy for Peritonsillar Abscess

Objective: 1) Compare operative time and intraoperative blood loss in patients receiving either Quinsy or interval tonsillectomy for peritonsillar abscess. 2) Compare postoperative bleeding and readmission rates for patients receiving either Quinsy or interval tonsillectomy for peritonsillar abscess.

Method: Study design: Retrospective review. Setting: Academic tertiary pediatric hospital. Patients: Children treated between 2007 and 2011 for peritonsillar abscess. Patients were identified by searching the hospital database for all children treated for the ICD-9 code 475 (peritonsillar abscess). Children who never received a tonsillectomy (CPT codes 42820/42821/42825/42826) were excluded.

Results: A total of 49 children received tonsillectomy for peritonsillar abscess from 2007 to 2011. Of these, 37 received a Quinsy tonsillectomy, and 12 received antibiotics with or without incision and drainage, followed by tonsillectomy a minimum of 2 weeks later. Total hospital days in treatment course was 2.2 days for the Quinsy tonsillectomy group and 2.3 days for the interval tonsillectomy group. Estimated blood loss was less than 20 milliliters for both groups. Operative time was 38 minutes for Quinsy tonsillectomy and 39 minutes for interval tonsillectomy. There were no posttonsillectomy hemorrhages. One patient in the interval tonsillectomy group required readmission for dehydration.

Conclusion: There were no significant differences in total hospital days, blood loss, operative time, or postoperative complications between Quinsy tonsillectomy and interval tonsillectomy in the treatment of pediatric peritonsillar abscess.

Survey of Ménière's disease in a subspecialty referral practice

OBJECTIVES

To define the prevalence of definite Ménière's disease (MD) among patients presenting with characteristic symptoms and examine the utility of published diagnostic guidelines.

STUDY DESIGN AND SETTING

Retrospective review in an academic referral practice.

RESULTS

The prevalence of definite MD in these 295 individuals was 64%. The next-largest group (23%) consisted of patients with only cochlear symptoms. Those initially classified as probable are usually reclassified as definite with extended follow-up. Of those with definite MD, the mean duration of disease at last follow-up was 7.6 years, 56% were female, 19% had bilateral disease, and 34% required surgical management for vertigo.

CONCLUSIONS

The 1995 AAO-HNS guidelines are useful for classification of MD according to certainty of diagnosis and severity of disease, though some modifications could be considered.

SIGNIFICANCE

Application of consistent diagnostic criteria is essential for epidemiological, genetic, or outcomes studies of Ménière's disease.

Effects of polyethylene glycol on stability of α-chymotrypsin in aqueous ethanol solvent

The effects of polyethylene glycol (PEG) of different molecular weights (400, 2000, 6000, 12,000, 20,000, and 35,000) on the conformational stability and catalytic activity of alpha-chymotrypsin in 60% ethanol were studied. The inactivation caused by the organic solvent was not influenced by PEG 400. However, the PEGs with higher molecular weights up to 35,000 increased the stability of the enzyme, but this alpha-chymotrypsin stabilizing effect was molecular weight-independent. With increase of the molecular weight of PEG, a more stable tertiary structure of the enzyme was observed.

Effects of Ca2+ on catalytic activity and conformation of trypsin and alpha-chymotrypsin in aqueous ethanol

The effects of calcium ions on the conformation and catalytic activity of trypsin and alpha-chymotrypsin were studied in aqueous ethanol. The activity of alpha-chymotrypsin was practically lost within 10 min in the presence of 60% ethanol while trypsin preserved about 40% of its original activity even in 85% ethanol at pH 3. The catalytic activity of alpha-chymotrypsin did not decrease in the presence of 1.2M CaCl2 and 0.6M CaCl2 with trypsin in ethanolic solvent. In the latter case an activation of enzyme was observed. The stabilizing effects of calcium ions were accompanied by an increase in the helical content in both enzymes, as followed by circular dichroism measurements.

Effects of polyhydroxy compounds on the structure and activity of alpha-chymotrypsin

The effects of glycerol, polyethylene glycol, fructose, glucose, sorbitol, and saccharose on the conformation and catalytic activity of alpha-chymotrypsin were studied in 0.1 M sodium phosphate buffer and buffered aqueous 60% ethanol (pH 8.0). The enzyme activity was practically completely lost within 10 min in 60% ethanol, but in the presence of stabilizers the activity was retained. With the exception of polyethylene glycol, the stabilizing effect decreased with increase of the incubation time. The preservation of the catalytic activity was accompanied by changes in the secondary and tertiary structures of alpha-chymotrypsin.

Structure and activity of alpha-chymotrypsin and trypsin in aqueous organic media

The effects of different concentrations (20-95%) of organic solvents (ethanol, 1,4-dioxane and acetonitrile) were studied on alpha-chymotrypsin and trypsin from bovine pancreas. The changes in secondary structure were followed by CD measurements, and the apparent Michaelis constants (KMapp) and the stabilities of the enzymes were determined. Significant alterations in the CD spectra were found for both enzymes at the different organic solvent concentrations. The apparent KM values of trypsin and alpha-chymotrypsin decreased as the low solvent concentrations were elevated, but then increased in the presence of higher organic solvent concentrations. The stabilities of the enzymes changed on increase of the organic solvent concentration; trypsin exhibited a higher stability than that of alpha-chymotrypsin in all organic solvents. These results show that at an organic solvent content of 95% the manifestation of an enzyme activity similar to that measured in water can be attributed to the similar compositions of the secondary structural elements.

An examination of the assumptions of specialization, mental disorder, and dangerousness in sex offenders

Sex offenders have been singled out for differential treatment by the legal and mental health systems. This article attempts to inform law reform efforts and criminal justice mental health policy by examining the assumptions underlying differential legal and mental health treatment of sex offenders. These assumptions include the theories that sex offenders are mentally disordered and in need of treatment, specialists in sex crimes, and more dangerous than other criminal offenders. Empirical findings demonstrate that sex offenders are not specialists in sex crimes and are not mentally disordered. Examination of past research suggests that sex offenders are not at more risk than other criminal offenders to commit future sex crimes. Implications of research findings for selective prosecution of sex crime cases, mental health policy, sex offender legislation, and predictions of future dangerousness are discussed. Proposals for future research needs and law reform are presented.

Effects of synthetic pyrethroids and methidation on activities of some digestive enzymes in carp (Cyprinus carpio L.)

The effects of pyrethroid pesticides (deltamethrin, permethrin and cypermethrin) and an organophosphate ester (methidation) on the activities of carp trypsin, alpha-chymotrypsin, carboxypeptidase A and lipase were studied. The enzymes were isolated from the gastrointestinal tract and the effects of the pesticides were investigated during incubation for 5 min. The activity of trypsin was influenced only slightly by the presence of deltamethrin and methidation, whereas permethrin and cypermethrin caused significant inhibition. The pyrethroid pesticides at lower concentrations resulted in a slight activation of alpha-chymotrypsin. Methidation inhibited the alpha-chymotrypsin activity by about 20%. These pesticides modified the lipase activity to a lesser extent; the highest inhibition was measured with cypermethrin. The carboxypeptidase A activity was inhibited by both pyrethroid pesticides and methidation. The results suggest that these pesticides might interact with the active conformation of the studied hydrolytic enzymes, resulting in changes in their activities.

Carboxypeptidase A-catalyzed dipeptide synthesis in organic media

The carboxypeptidase A-catalyzed syntheses of dipeptides from L-amino acids (Phe, Tyr, Trp, Leu and Ile) were studied in various water-miscible (acetone, acetonitrile, ethanol, methanol and 1,4-dioxane) organic solvents. The highest yield (43%) was achieved in acetonitrile with L-Phe as substrate, after a 24-h incubation. The optimal conditions of Phe-Phe synthesis in acetonitrile were determined. For maximal conversion 1.2 mM L-Phe, 1.4 mg ml-1 enzyme and about 10% water are needed in buffered aqueous acetonitrile (pH 5.5) at 30 degrees C.

Acute injuries in off-road bicycle racing

A descriptive study was conducted to investigate injuries sustained at a major off-road bicycling race at Mammoth Mountain, California, July 6 to 10, 1994. A total of 4027 individual starts in five events during the race were reported. Overall, the total number of competitors in the 5 events was 3624, with some cyclists participating in multiple events. Injuries were considered significant if they occurred during competition and prevented the rider from completing the event. Sixteen cyclists had injuries that met these criteria for an overall injury rate of 0.40%. These 16 cyclists had 44 injuries. Abrasions were the most common injury, followed by contusions, lacerations, fractures, and concussions. The mean injury severity score was 3.0 (range, 1 to 5) with 81.2% of the injuries resulting from cyclists going downhill. Injuries were more severe when the riders were thrown from the bicycles (P = 0.03). We observed different mechanisms of injury in various events, suggesting that the risk factors for sustaining a traumatic injury may vary according to the type of competition involved.

Coenzyme production using immobilized enzymes. III. Immobilization of glucose-6-phosphate dehydrogenase from bakers' yeast

Glucose-6-phosphate dehydrogenase (D-glucose-6-phosphate: NADP+ 1-oxidoreductase, EC 1.1.1.49) from Bakers' yeast was immobilized with the highest activity on polyacrylamide beads possessing carboxylic functional groups activated by a water-soluble carbodiimide. The optimal pH values for the catalytic activity of the soluble and the immobilized glucose-6-phosphate dehydrogenase were practically identical, lying between pH 9.0 and 9.2. The optimal temperature for both the soluble and the immobilized enzyme was about 50 degrees C. The apparent Km values of the immobilized enzyme were slightly higher than those of the soluble enzyme. The immobilization improved the stability of the enzyme in the pH range 6.0-9.0 at 45 degrees C. The operational stability of the immobilized glucose-6-phosphate dehydrogenase proved favorable in a column experiment during 37 days of operation.

Endotoxin and pulmonary cell injury

The physiopathologic similarity between adult respiratory distress syndrome (ARDS) secondary to sepsis and endotoxin-induced pulmonary abnormalities has provided extensive descriptive information confirming bacterial endotoxin as a factor initiating the heterogeneous pulmonary changes in ARDS. The present studies have used an established in vitro model for pulmonary cell injury to examine bacterial endotoxin 1, as a direct cytotoxic agent on the two major alveolar cell types, pulmonary endothelium and epithelium; 2, as a stimulant of neutrophil-mediated pulmonary cell injury, and 3, to examine effector mechanisms of cell-mediated damage by studying the potential effectiveness of antioxidants and antiproteolytic agents in the inhibition of this process. Endotoxin direct toxicity and stimulation of neutrophil-mediated pulmonary cell injury was observed in both pulmonary cell populations in systems free of activated serum complement. Endothelial cells were observed to be more susceptible to both the direct effect of endotoxin and to neutrophil-mediated injury when compared with epithelial cell derived monolayers. The addition of an antiprotease (soybean trypsin inhibitor [STI]) was superior to antioxidants (catalase, superoxide dismutase) in reducing the neutrophil-mediated endothelial toxicity (stimulated 51CR per cent release) observed. A 92 per cent degree of protection was observed with the highest dose of STI (5 milligrams per milliliter) used. Proteases released by activated neutrophils on endotoxin stimulation appear to be the predominant toxic species responsible for endothelial injury in this system.

Immobilization of lactate dehydrogenase on polyacrylamide beads

Pig muscle lactate dehydrogenase (L-lactate:NAD oxidoreductase, EC 1.1.1.27) was covalently immobilized on polyacrylamide beads containing carboxylic functional groups activated by water-soluble carbodiimide. The effects of immobilization on the catalytic properties and stability of the lactate dehydrogenase were studied. There was no shift in the pH optimum of the immobilized enzyme compared to that of the soluble one. The apparent optimum temperature of the soluble enzyme was 65 degrees C, while that of the immobilized enzyme was between 50 and 65 degrees C. The apparent Km values of the immobilized enzyme with pyruvate and NADH substrates were higher than those of the soluble enzyme. As a result of immobilization, enhanced stabilities were found against heat treatment, changes in pH, and urea denaturation.

Comparative studies on soluble and immobilized rabbit muscle pyruvate kinase

Rabbit muscle pyruvate kinase was immobilized by covalent attachment to a polyacrylamide support (Akrilex C) containing carboxylic functional groups. As a result of immobilization, the pH optimum for catalytic activity shifted into a more alkaline direction. The apparent Km value with phosphoenolpyruvate increased, and that with ADP slightly decreased. With respect to the stability against urea and thermal inactivation, the immobilized pyruvate kinase seemed to be the more stable at lower urea concentrations and between 45 and 55 degrees C. At 1.5 and 2.5M urea and at higher temperature, there were no marked differences between the soluble and the immobilized enzyme.

Studies on the properties of glucose-6-phosphatase from carp liver microsomes (Cyprinus carpio L.)

The effects of temperature and pH on the phosphohydrolase activity of carp hepatic glucose-6-phosphatase (EC 3.1.3.9) have been investigated. The enzyme activity was maximum at about 308 K and in the pH range 5-6.5. The apparent Michaelis constant (KM) and Vmax of the reaction with glucose-6-phosphate were found to be 14.8 mM and 2.27 nmol/min/mg protein. The enzyme activity was partly inhibited by EDTA, while in the presence of sufficient PCMB virtually total inhibition was observed.

Decreased bactericidal function and impaired respiratory burst in lung macrophages after sustained in vitro hyperoxia

Lung macrophages (LM) play a crucial role in pulmonary bacterial defense. High inspired oxygen concentrations are used in a variety of diseases and "oxygen toxicity" could impair antibacterial function. We therefore examined the effect of sustained in vitro hyperoxia on LM bactericidal function, and on generation of two bactericidal oxygen metabolites. The LM were cultivated under aerobic (PO2 approximately 140 mmHg) or hyperoxic (PO2 approximately 630 mmHg) conditions for 48 h, and then incubated with Staphylococcus aureus labeled with 3H thymidine for 30 min. Incubated monolayers were processed for measurement of total bacterial uptake and for number of viable intracellular bacteria. Superoxide anion (O2-) and hydrogen peroxide (H2O2) generation was determined in similarly cultivated cells stimulated with opsonized zymosan. The results indicate that the bacterial killing capacity of oxygen-cultivated LM is significantly decreased (p less than 0.001). In addition, a significant (p less than 0.001) decrease in generation of O2- and H2O2 was noted after exposure to high oxygen tensions. The data suggest that decreased bactericidal function after sustained hyperoxia may be due to an impairment of a specific bactericidal mechanism, i.e., an impaired "respiratory burst."

Transepithelial transport in cell culture: bioenergetics of Na-, D-glucose-coupled transport

The renal cell line LLC-PK1 cotransports Na and D-glucose from the apical to the basolateral side of the cell monolayer, and the short-circuit current (Isc) measures the net amount of Na transported. Under conditions of maximal cotransport, the addition of phlorizin or removal of Na reversibly decreased oxygen consumption by one-half. In the absence of glycolytic substrates, alpha-methyl-D-glucoside stimulated Isc and oxygen consumption, although the Isc came to a steady state 50% less than when glycolytic substrates were present. The addition of other aerobic substrates did not increase Isc; however, when non-cotransported glycolytic substrates were introduced the Isc returned to a maximum with an associated fall in oxygen consumption and increased lactate production. Thus, in the absence of glycolytic substrates aerobic ATP formation may be rate-limiting for Na, D-glucose cotransport. For this epithelium glycolysis makes an important contribution to the provision of energy for transport. Oxygen consumption does not correlate well with Isc and is not a good measure of the energy used in transport.

Studies on the effect of paraquat on glycogen mobilization in liver of common carp (Cyprinus carpio L.)

1. A herbicide, paraquat (1,1'dimethyl-4,4'-bipyridilium-dichloride) was administered to carp in 0.5-10.0 ppm concentrations, respectively, and blood sugar level, glucose-6-phosphatase and glycogen phosphorylase activities of liver were determined. 2. Paraquat treatment caused an increase of blood sugar level and enhanced phosphorylase and glucose-6-phosphatase activities. 3. Paraquat can induce alterations in endoplasmic reticulum that might contribute to the changes in glucose-6-phosphatase activity, resulting in an increase of blood glucose level and/or all the effects can be attributed to a high level of circulating epinephrine produced by paraquat toxicosis.

Lung cell oxidant injury. Enhancement of polymorphonuclear leukocyte-mediated cytotoxicity in lung cells exposed to sustained in vitro hyperoxia

The oxidant damage of lung tissue during in vivo hyperoxic exposure appears to be amplified by neutrophils that release toxic amounts of oxygen metabolites. In our studies cloned lung epithelial cells (L2 cells), lung fibroblasts, and pulmonary artery endothelial cells were cultured under either ambient (Po(2) approximately 140 torr) or hyperoxic (Po(2) approximately 630 torr) conditions for 48 h (24 h for endothelial cells). After cultivation, phorbol myristate acetate- or opsonized zymosan-stimulated neutrophils were added to the cultivated monolayers for 4 h, and lung cell damage was quantitated using (51)Cr release as an index. The data show that stimulated neutrophils are able to injure the three lung cell lines tested, with endothelial cells being highly susceptible to this injury and L2 cells being slightly more susceptible than lung fibroblasts. The studies also demonstrate that all three lung cell lines exposed to sustained hyperoxia are more susceptible to neutrophil-mediated cytotoxicity than their time-matched air controls. Hydrogen peroxide was the main toxic oxygen metabolite because catalase (2,500 U/ml) completely protected the target cells. Equivalent quantities of hydrogen peroxide generated by glucose oxidase instead of by neutrophils gave a similar degree of target cell injury. Superoxide dismutase at high concentrations (250 mug/ml) provided some protection. Other systems that detoxify oxygen metabolites were without protective effect. These findings indicate that the increase in susceptibility of lung cells to neutrophil-mediated oxidant damage is a toxic effect of hyperoxia on lung cells. This specific manifestation of oxygen damage provides insight into the integration between primary mechanisms (oxygen exposure) and secondary mechanisms (release of oxygen metabolites by neutrophils) with respect to the cellular basis for pulmonary oxygen toxicity.

Differences in oxygen-dependent regulation of enzymes between tumor and normal cell systems in culture

Metabolic studies in tumor cells have indicated that bioenergetic regulatory mechanisms geared to acute changes in oxygen availability are abnormal. In the present studies we have examined bioenergetic adaptations to chronic oxygen depletion in culture maintained tumor cells in comparison to normal cell lines. Activities of two key glycolytic enzymes (pyruvate kinase (PyKI) and phosphofructokinase (PFK)) were measured in two tumor cell lines (fibrosarcoma (FS) and Hela) and two normal cell lines (rat lung fibroblasts (RLF) and WI-38) maintained in culture for up to 96 hours under aerobic (PO2 approximately 140) and hypoxic PO2 approximately 15) conditions. Exposure to low O2 tensions for 96 hours resulted in significant increases in PyKi and PFK in both RLF and WI-38, ut did not alter activities of these enzymes in either FS or HeLa cell systems. Activities of two enzymes involved in O2 metabolism (cytochrome oxidase (CyOx) and superoxide dismutase (SOD) were also measured in the two tumor cell lines and in RLF. chronic hypoxia significantly decreased the activities of CyOx and SOD in RLF cell systems but did not alter the activities of these enzymes in the tumor cells. In these studies, the tumor-derived cell lines do not demonstrate specific enzymatic responses to sustained oxygen depletion in vitro noted in normal cell systems, suggesting significant abnormalities in regulatory mechanisms geared to chronic changes in molecular O2.

Bioenergetic alterations in cultivated pulmonary artery and aortic endothelial cells exposed to normoxia and hypoxia

Endothelial cells function under conditions of different oxygen availability under physiologic conditions and a variety of pathologic states. We determined the effect of normal and low O2 tensions on three key bioenergetic enzymes [pyruvate kinase (ATP:pyruvate phosphotransferase, EC 2.7.1.40), phosphofructokinase (ATP:D-fructose-6-phosphate 1-phosphotransferase, EC 27.1.11) and cytochrome aa3] in culture-maintained endothelial cells derived from calf pulmonary artery and aorta. Endothelial cells derived from pulmonary artery and aorta demonstrate similar bioenergetic enzyme activities when exposed to the same PO2 in vitro. Endothelial cells exposed to hypoxia in vitro for 48-96 hr show significantly increase activities of 2 key glycolytic enzymes: pyruvate kinase, and phosphofructokinase. Freshly isolated intimal strips from calf pulmonary artery (normal PO2 = 40 torr) show significantly greater activities of PyKi than aortic intimal strips (normal PO2 = 90 torr), suggesting that a similar pattern occurs in vivo. The data suggest that both cell types have a common bioenergetic pattern which is genetically determined and that this pattern is modified by regulatory mechanisms geared to ambient O2 tension. As endothelial cells of both types are not uncommonly exposed to hypoxic conditions, these regulatory mechanisms may play an important role in maintaining vascular integrity.

Adaptations of phagocytosis and pinocytosis in mouse lung macrophages after sustained in vitro hypoxia

Alterations in lung macrophage function after chronic hypoxia have not been clearly defined. In the present studies, we examined the effect of in vitro O2 depletion (PO2 approximately 15 mmHg) for as long as 96 h on lung macrophage endocytosis. In addition, we compared the effect of an acute decrease in O2 availability on endocytic function in lung macrophages maintained for 96 h under either aerobic or hypoxic conditions. Chronic hypoxia did not result in a decreased capacity for phagocytosis. In addition, in contrast to air-maintained cells, lung macrophages exposed to low PO2 for 96 h showed no impairment in phagocytic function during acute O2 depletion. Chronic hypoxia did produce a reversible impairment in pinocytosis. However, as with phagocytosis, pinocytosis in lung macrophages pre-exposed to low PO2 for 96 h was not decreased by acute hypoxia. In these in vitro studies, chronic hypoxia appeared to produce lung macrophage adaptations that served to maintain function, despite severe O2 depletion. These adaptations may be important with respect to pinocytic and phagocytic function in clinical conditions associated wtih sustained alveolar hypoxia.

Regulation of glycolytic enzyme activity during chronic hypoxia by changes in rate-limiting enzyme content. Use of monoclonal antibodies to quantitate changes in pyruvate kinase content

Monoclonal antibodies were prepared against pyruvate kinase (PyKi; ATP: pyruvate phosphotransferase, EC 2.7.1.40) and used to quantitate PyKi content in L2 lung cells and WI-38 fibroblasts cultivated under hypoxic and normoxic conditions. After 96 h of hypoxic cultivation, PyKi activity was significantly increased in both cell types (L2: normoxia [Po2 = 142 torr], 0.11 +/- 0.01 [SD]; hypoxia [Po2 = 14 torr], 0.25 +/- 0.04 U/microgram DNA, P < 0.01). PyKi content increased proportionately in both cell lines (L2: normoxia, 0.44 +/- 0.13; hypoxia, 0.94 +/- 0.13 microgram enzyme protein/microgram DNA). Specific activity was not significantly different after 96 h (L2: normoxia, 261 +/- 11; hypoxia, 261 +/- 14 U/mg enzyme protein). These results indicate that regulation of glycolysis during chronic hypoxia occurs at the level of enzyme content. Chronic O2 depletion leads to either an increased rate of biosynthesis or a decreased rate of biodegradation of PyKi, causing augmented glycolytic capacity. Monoclonal antibodies provide a highly specific, convenient approach to charcterizing enzymes, as well as quantitating cellular enzyme content.

Impairment of phagocytosis by moderate hyperoxia (40 to 60 per cent oxygen) in lung macrophages

Exposure of isolated mouse lung macrophages to 40 and 60 per cent oxygen in tissue culture for 48 hours resulted in significant depression of phagocytosis as compared to air-exposed controls. The impairment of phagocytosis was reversed when the cells were reexposed to normoxic conditions for 48 hours. The impairment of phagocytosis occurred despite significant increases in intracellular superoxide dismutase activity, an enzyme felt to play a protective role in oxygen toxicity. Exposure to 40 and 60 per cent oxygen increased the susceptibility of lung macrophages to functional impairment by 95 per cent oxygen, rather than producing tolerance. The precise biologic and clinical significance of these findings will require additional studies in integrated systems. However, these studies show unequivocal lung macrophage injury with moderate hyperoxic exposure.

Bioenergetic pattern of turtle brain and resistance to profound loss of mitochondrial ATP generation

The adaptations in the freshwater turtle that permit survival despite prolonged loss of mitochondrial ATP generation were investigated by comparing the bioenergetics of turtle brain slices with rat brain slices. Aerobic turtle brain shows no significant difference in basal levels of total ATP generation compared to rat brain; levels in turtle brain and rat brain were 18.4 +/- 2.8 (SD) and 19.4 +/- 2.2 mumol (100 mg of tissue)-1 hr-1, respectively. However, in turtle brain, a significantly greater fraction of ATP is derived from glycolysis both under aerobic and anaerobic conditions [aerobic turtle (24%) and rat (13%), P less than 0.02; anaerobic, turtle (28%) and rat (18%), P less than 0.05]. The increased glycolytic capacity is related to high levels of rate-limiting glycolytic enzymes, such as pyruvate kinase (EC 2.7.1.40). Turtle brain operates close to glycolytic capacity even under aerobic conditions, and no Pasteur effect can be demonstrated. Quantitatively, anaerobic glycolysis accounts for a maximum of 28% of basal aerobic ATP generation, suggesting that prolonged diving is also accompanied by a reduction in brain energy requirements. The adaptation subserving short-term (natural) diving is an increase in brain glycolytic capacity. The adaptation subserving prolonged diving (days to weeks) may be a reduction in the energy requirements of brain (and other cells).

Effects of high oxygen exposure on bioenergetics in isolated type II pneumocytes

O2-mediated alterations in cell energy metabolism may play a role in structural and functional abnormalities described in type II pneumocytes (T-II-P) following in vivo hyperoxia. Bioenergetic alterations produced by hyperoxia (95% O2) were therefore examined in a culture-maintained cell line derived from T-II-P. Exposure of cell monolayers to 95% O2 for 96 h results in a significant decrease in O2 consumption (from 0.52 +/- 0.07 to 0.30 +/- 0.08, P less than 0.01), suggesting impaired mitochondrial energy provision. In addition, there are increased rates of aerobic lactate production (from 2.89 +/- 0.52 to 3.84 +/-0.80, P less than 0.05) with loss of Pasteur effect, indicating a shift to glycolytic metabolism at relatively high PO2's. These metabolic changes are not accompanied by altered activities of critical mitochondrial (cytochrome oxidase) or glycolytic (pyruvate kinase, phosphofructokinase) enzymes. Altered cell bioenergetics following hyperoxia may this represent an important secondary mechanism leading to functional abnormalities in T-II-P.

Effects of sustained oxygen depletion on tissue pyruvate kinase activities in the freshwater turtle, Pseudemys scripta elegans

1. The effect of sustained (48 hr) oxygen depletion on tissue (brain, heart, skeletal muscle) pyruvate kinase (PyKi) activities was examined in the pond turtle (Pseudemys scripta elegans). 2. PyKi activities in skeletal muscle are significantly increased (from 322 +/- 84 to 450 +/- 95) following 48 hr of tissue hypoxia. PyKi activities in brain may already be elevated under ambient conditions but do not change following prolonged submersion (334 +/- 75 vs 325 +/- 77). Cardiac muscle PyKi is actually decreased (from 135 +/- 35 to 94 +/- 18) under anaerobic conditions. 3. The data suggest that prolonged O2 depletion may increase PyKi biosynthesis in turtle skeletal muscle (subserving enhanced glycolysis), but also demonstrate that factors other than oxygen availability are involved in the regulation of tissue PyKi activities in intact vertebrates.

Bioenergetic pattern of isolated type II pneumocytes in air and during hypoxia

The bioenergetic pattern of a cell clone derived from rat lung with ultrastructural and biochemical characteristics like those of type II pneumocytes (T-II-P), has been studied in a tissue culture system. During air cultivation, these cells have a high rate of aerobic and anaerobic glycolysis associated with high activities of two rate-limiting enzymes in glycolysis (pyruvate kinase [PyKi] and phosphofructokinase [PFK]). This is present despite the rates of oxygen consumption and activities of cytochrome oxidase (CyOx) similar to other lung cells. Presumably the high rate of aerobic glycolysis explains the substantial lactate production previously described in lung slices and in the intact perfused lung. Hypoxic cultivation results in a decrease in CyOx. Acute re-exposure to air does not restore the oxygen consumption to normal, presumably as a result of decreased mitochondrial O(2) utilization associated with decreased CyOx activity. As a result, hypoxically cultivated T-II-P cells have a decreased capacity for mitochondrial ATP generation in air as compared to air-cultivated cells. During hypoxia, aerobic and anaerobic glycolysis are further increased as well as the activities of PyKi and PFK. The high rate of glycolysis and high activities of PyKi and PFK in cultivated T-II-P appear to reflect intrinsic genetic regulation. The decreased CyOx activity and increased PyKi and PFK activities in hypoxic T-II-P appear to reflect alterations in enzyme biosynthesis/biodegradation regulated by O(2) availability.