A framework for future national pediatric pandemic respiratory disease severity triage: The HHS pediatric COVID-19 data challenge

Introduction

With persistent incidence, incomplete vaccination rates, confounding respiratory illnesses, and few therapeutic interventions available, COVID-19 continues to be a burden on the pediatric population. During a surge, it is difficult for hospitals to direct limited healthcare resources effectively. While the overwhelming majority of pediatric infections are mild, there have been life-threatening exceptions that illuminated the need to proactively identify pediatric patients at risk of severe COVID-19 and other respiratory infectious diseases. However, a nationwide capability for developing validated computational tools to identify pediatric patients at risk using real-world data does not exist.

Methods

HHS ASPR BARDA sought, through the power of competition in a challenge, to create computational models to address two clinically important questions using the National COVID Cohort Collaborative: (1) Of pediatric patients who test positive for COVID-19 in an outpatient setting, who are at risk for hospitalization? (2) Of pediatric patients who test positive for COVID-19 and are hospitalized, who are at risk for needing mechanical ventilation or cardiovascular interventions?

Results

This challenge was the first, multi-agency, coordinated computational challenge carried out by the federal government as a response to a public health emergency. Fifty-five computational models were evaluated across both tasks and two winners and three honorable mentions were selected.

Conclusion

This challenge serves as a framework for how the government, research communities, and large data repositories can be brought together to source solutions when resources are strapped during a pandemic.

Quantifying the competitiveness of the electronic health record market and its implications for interoperability

OBJECTIVE

The objective of this study was to quantify both the competitiveness of the EHR vendor market in the United States of America (US) and the degree of fragmentation of individual Medicare beneficiaries' medical records across the differing EHR vendors found in the US healthcare system.

METHODS AND MATERIALS

We determined the Part A and Part B Medicare-expenditure weighted market shares of EHR vendors and estimated the rate of attestation of meaningful use (MU) for EHRs among Medicare Part A & B providers from 2011 to 2016. Based on these data we calculated the annual Herfindahl-Hirschman Index to quantify the competitiveness of the EHR market as well as the number of vendors individual Medicare beneficiaries' medical records were stored in for the period 2014-2016.

RESULTS

We find that as of 2016 the EHR vendor environment was competitive but trending towards becoming highly concentrated soon. We also found that patient medical records were highly fragmented as only 4.5 % of expenditure-weighted individual Medicare beneficiaries had their MU medical records associated with a single vendor, while 19.8 % of expenditure-weighted beneficiaries had their MU medical records stored in 8 or more vendors.

DISCUSSION

These results indicate that there are tradeoffs between EHR market competition, and the challenges associated with achieving interoperability across numerous competing vendors.

CONCLUSION

Uncertainty of interoperability among different EHR vendors may make transmission of medical records among different providers challenging, mitigating the benefit of vendor competition. This highlights the critical importance of current interoperability efforts moving forward.

Societal willingness to pay to avoid mortality and morbidity from Clostridioides difficile and carbapenem-resistant Enterobacteriaceae infections in the United States

BACKGROUND

Clostridioides difficile infection (CDI) is among the most common health care-associated infections in the United States and is increasingly affecting the elderly. Although carbapenem-resistant Enterobacteriaceae (CRE) infections are still relatively uncommon, there are reported increases in the rate of infection for certain strains, such as Klebsiella pneumoniae. This study examines the burden of mortality and morbidity for CDI and CRE infections in the United States and estimates the societal willingness to pay to avoid them.

METHODS

We use an analytic model to estimate the number of incident cases and associated health outcomes for CDI and CRE infections.

RESULTS

The number of CDI and CRE infection incident cases in the United States in 2016, is estimated at 468,567 and 9,620, respectively. These infections result in a total of 17,630 estimated deaths and 8,624 lost quality-adjusted life years among patients who survive per year.

CONCLUSIONS

Given the significant mortality and morbidity from these infections, the estimated societal willingness to pay to avoid them is high at $176.7 billion per year, of which 93.9% ($166.0 billion) is for CDI. Our estimates far exceed the medical care costs for CDIs and CRE infections reported in the literature despite not capturing the additional costs borne by third-party payers. As incident cases increase or resistant strains develop, the societal willingness to pay is also expected to increase.

Surgical resection of a massive primary mediastinal liposarcoma with cervical extension

A 73-year-old man was referred for surgical excision of a massive mediastinal and cervical liposarcoma following neoadjuvant chemotherapy. Surgery was performed via a cervical incision, sternotomy and right posterolateral thoracotomy. The tumour arose from the oesophagus, which underwent extensive dissection and was oversewn with pleura after tumour resection. Histology confirmed a completely excised grade 2 de-differentiated liposarcoma with complete macroscopic excision. The patient made an excellent recovery. Oesophageal liposarcomas are rare and, unlike in this case, often extend intraluminally, necessitating oesophagectomy. To our knowledge, this is the largest such tumour found in the literature.

Promoting Antibacterial Drug Development: Select Policies and Challenges

BACKGROUND

The development pipeline for antibacterial drugs has not met the demand of hospitals and healthcare providers struggling to cope with increasing problems of antibacterial resistance. Although the challenges associated with antibacterial drug development have been known for some time, previous efforts to address them have not been sufficient. There remains an urgent need for targeted incentives to foster antibacterial drug development while encouraging prudent use.

OBJECTIVE

We examine the effects of two types of incentives, a 5-year delay in competition from generics and a lump-sum US$50 million prize payment upon successful US Food and Drug Administration approval, on antibacterial drug company returns.

METHODS

We use the decision-tree framework developed in a study for the US Department of Health and Human Services, which models the drug company's decision process as a revenue maximizer under uncertainty.

RESULTS

Our results show that, to maximize societal benefit, such incentives need to take into consideration the indication(s) the new antibacterial drug is designed to treat as well as the drug development stage.

CONCLUSIONS

Optimal policies should maximize the difference between societal benefit, primarily measured as the reduction in public health burden from the development of a new antibacterial drug that treats an infectious disease while ensuring prudent use, and social cost. Here, we show that the two types of policies examined under-incentivize early-stage developers (i.e., do not achieve the desired outcome) and over-incentivize late-stage developers (i.e., achieve the desired outcome but at a cost that is higher than needed) ceteris paribus.

Key cost drivers of pharmaceutical clinical trials in the United States

Background:

The increasing cost of clinical research has significant implications for public health, as it affects drug companies’ willingness to undertake clinical trials, which in turn limits patient access to novel treatments. Thus, gaining a better understanding of the key cost drivers of clinical research in the United States is important.

Purpose:

The study which is based on a report prepared by Eastern Research Group, Inc., for the US Department of Health and Human Services, examined different factors, such as therapeutic area, patient recruitment, administrative staff, and clinical procedure expenditures, and their contribution to pharmaceutical clinical trial costs in the United States by clinical trial phase.

Methods:

The study used aggregate data from three proprietary databases on clinical trial costs provided by Medidata Solutions. We evaluated per-study costs across therapeutic areas by aggregating detailed (per patient and per site) cost information. We also compared average expenditures on cost drivers with the use of weighted mean and standard deviation statistics.

Results:

Therapeutic area was an important determinant of clinical trial costs by phase. The average cost of a Phase 1 study conducted at a US site ranged from US$1.4 million (pain and anesthesia) to US$6.6 million (immunomodulation), including estimated site overhead and monitoring costs of the sponsoring organization. A Phase 2 study cost from US$7.0 million (cardiovascular) to US$19.6 million (hematology), whereas a Phase 3 study cost ranged from US$11.5 million (dermatology) to US$52.9 (pain and anesthesia) on average. Across all study phases and excluding estimated site overhead costs and costs for sponsors to monitor the study, the top three cost drivers of clinical trial expenditures were clinical procedure costs (15%–22% of total), administrative staff costs (11%–29% of total), and site monitoring costs (9%–14% of total).

Limitations:

The data were from 2004 through 2012 and were not adjusted for inflation. Additionally, the databases used represented a convenience, that is, non-probability, sample and did not allow for statistically valid estimates of cost drivers. Finally, the data were from trials funded by the global pharmaceutical and biotechnology industry only. Hence, our study findings are limited to that segment.

Conclusion:

Therapeutic area being studied as well as number and types of clinical procedures involved were the key drivers of direct costs in Phase 1 through Phase 3 studies. Research shows that strategies exist for reducing the price tag of some of these major direct cost components. Therefore, to increase clinical trial efficiency and reduce costs, gaining a better understanding of the key direct cost drivers is an important step.

Comparative effectiveness research in practice: the Drug Effectiveness Review Project experience

AIM

Assess the effect of the Drug Effectiveness Review Project's comparative effectiveness research findings on prescribing behavior independently and in conjunction with a Medicaid preferred drug list.

METHOD

We queried prescription drug claims and enrollment information from the 2001-2008 Medicaid Analytic eXtract and Medicaid Statistical Information System for 17 states using a Wilcoxon signed rank test design to evaluate the effects of the Drug Effectiveness Review Project's report release and preferred drug list implementation on ACE inhibitor prescribing behavior at a state level. The primary outcome of interest was the percentage of ACE inhibitor prescriptions that are defined as 'differentiated' based on the content of the Drug Effectiveness Research Program report.

RESULTS

The use of differentiated ACE inhibitors increased significantly in states that participated in the Drug Effectiveness Research Program and subsequently implemented a preferred drug list (p < 0.05, one-tailed). However, there was no significant change in utilization in nonparticipating states or in states that participated but did not subsequently implement a preferred drug list.

CONCLUSION

Although the publication of comparative effectiveness research findings may not directly influence practice, a preferred drug list can align utilization with clinical evidence. The states that participate in the Drug Effectiveness Review Project and use preferred drug lists have greater utilization of higher quality drugs, making the combination an effective strategy to translate comparative effectiveness research into practice.

Targeted therapies for pancreatic cancer

INTRODUCTION

Pancreatic cancer is a devastating malignancy and a leading cause of cancer mortality. Furthermore, early diagnosis represents a serious hurdle for clinicians, as symptoms are non-specific and usually manifest in advanced, treatment-resistant stages of the disease.

SOURCES OF DATA

Here, we review the rationale and progress of targeted therapies currently under investigation.

AREAS OF AGREEMENT

At present, chemoradiation regimes are administered palliatively, and produce only marginal survival benefits, underscoring a desperate need for more effective treatment modalities.

AREAS OF CONTROVERSY

Questions have been raised as to whether erlotinib, the only targeted therapy to attain a statistically significant increase in median survival, is cost-effective.

GROWING POINTS

The last decade of research has provided us with a wealth of information regarding the molecular nature of pancreatic cancer, leading to the identification of signalling pathways and their respective components which are critical for the maintenance of the malignant phenotype.

AREAS TIMELY FOR DEVELOPING RESEARCH

These proteins thus represent ideal targets for novel molecular therapies which embody an urgently needed novel treatment strategy.

Structural changes to airway smooth muscle in cystic fibrosis

BACKGROUND

Chronic airway obstruction is characteristic of cystic fibrosis (CF) but there are few studies of airway smooth muscle remodelling in CF.

METHODS

Airway smooth muscle content and mean airway smooth muscle cell size were measured by applying design-based stereology to bronchoscopic biopsy specimens obtained from seven subjects with CF and 15 healthy controls.

RESULTS

The smooth muscle content increased by 63% in subjects with CF (mean (SD) 0.173 (0.08) v 0.106 (0.042) mm(3) smooth muscle/mm(3) submucosa, mean difference -0.067; 95% CI -0.12 to -0.013, p = 0.017) but there was no increase in mean cell size (2705 (351) v 2654 (757) microm(3), mean difference -51; 95% CI -687 to 585, p = 0.87).

CONCLUSIONS

These findings indicate hyperplasia of airway smooth muscle cells without hypertrophy and suggest that accumulation of airway smooth muscle cells may contribute to airway narrowing and bronchial hyperresponsiveness in CF.

Allergen challenge causes inflammation but not goblet cell degranulation in asthmatic subjects

BACKGROUND

An allergen challenge to the airways of sensitized mice causes eosinophilic airway inflammation and degranulation of goblet cells, which lead to airway obstruction. However, whether allergen challenge causes a similar pattern of airway inflammation and goblet cell degranulation in human beings is unknown.

OBJECTIVE

The purpose of this study was to determine whether allergen challenge increases airway inflammatory cells and causes goblet cell degranulation in human subjects with asthma.

METHODS

In bronchial biopsy specimens taken from 8 asthmatic subjects at 1 and 24 hours after allergen challenge, we measured eosinophil and neutrophil numbers as indicators of inflammation. We also measured goblet cell mucin stores and the amounts of secreted mucin in bronchial lavage as indicators of goblet cell degranulation.

RESULTS

Airway eosinophil numbers at both 1 and 24 hours after allergen challenge were twice as high as those after diluent challenge. Changes in neutrophil numbers were smaller and statistically insignificant. Goblet cell mucin stores measured in tissue stained with alcian blue/periodic acid-Schiff did not decrease significantly from baseline to 1 hour and actually tended to increase at 24 hours. This increase was significant in the subgroup of subjects with normal stored mucin levels at baseline. Mucin-like glycoprotein concentrations in bronchial lavage did not change significantly at either time point.

CONCLUSION

Although allergen challenge in asthmatic subjects increases airway eosinophil numbers as early as 1 hour after challenge, this inflammatory response does not cause goblet cell degranulation. In fact, in subjects with normal baseline mucin stores, allergen challenge increases goblet cell mucin stores.

Mild and moderate asthma is associated with airway goblet cell hyperplasia and abnormalities in mucin gene expression

Excessive airway mucus is an important cause of morbidity and mortality in asthma, but the relationship between accumulation of mucus and goblet cell size, number, and function is incompletely understood. To address these questions, stored mucin in the epithelium and goblet cell size and number were measured morphometrically, and mucin gene expression was measured by polymerase chain reaction and immunohistochemistry in endobronchial biopsies from 13 subjects with mild and moderate asthma and from 12 healthy control subjects. Secreted mucin was measured in induced sputum. We found that stored mucin in the airway epithelium was three times higher than normal in the subjects with asthma (p < 0.005). Goblet cell size was similar in both groups, but goblet cell number was significantly higher in the subjects with asthma (93,043 +/- 15,824 versus 41,959 +/- 9,230/mm3, p < 0.05). In mild asthma (FEV1 > or = 80% pred, n = 7), the level of stored mucin was as high as in moderate asthma (FEV1 < 80% pred, n = 6), but the level of secreted mucin was significantly lower (28.4 +/- 6.3 versus 73.5 +/- 47.5 microg/ml, p < 0.05). Secreted mucin was inversely correlated with stored mucin for the whole asthma group (rs = -0.78, p = 0.007). MUC5AC was the predominant mucin gene expressed in healthy subjects and subjects with asthma, and MUC5AC protein was increased in the subjects with asthma. We conclude that even mild asthma is associated with goblet cell hyperplasia and increased stored mucin in the airway epithelium, whereas moderate asthma is associated with increased stored mucin and secreted mucin. These findings suggest that acute degranulation of hyperplastic goblet cells may represent a mechanism for asthma exacerbations in mild and moderate asthma and that chronic degranulation of goblet cells may contribute to chronic airway narrowing in moderate asthma.

Migration of endoclip into duodenum. A rare complication after laparoscopic cholecystectomy

The long-term effect of spilled clips within the abdominal cavity after laparoscopic cholecystectomy is unknown. However, most surgeons agree that the migration of clips has limited clinical consequences. A few cases have been reported of clips that have migrated into the common bile duct, causing stone formation and/or obstructions. We present a case of gallstone pancreatitis treated with laparoscopic cholecystectomy that was complicated by bile leakage from the cystic duct stump 1 day after the procedure. Although the leaking stump sealed itself spontaneously after the placement of a biliary stent, a clip had migrated directly to the superior wall of the first portion of the duodenum. Herein the details of the patient's history are presented. We also discuss the possible mechanisms of clip migration and describe some preventive measures.

Abdominal wall abscess secondary to spilled gallstones: late complication of laparoscopic cholecystectomy and preventive measures

Spilled gallstones left in the abdominal cavity or trapped at trocar sites may cause considerable morbidity. We saw a patient with an abdominal wall abscess 2 years after laparoscopic cholecystectomy secondary to spilled stones. After we reviewed the operative procedure in addition to the accumulated experience in laparoscopic surgery, we believe that retrieval of specimens and their contents is of paramount importance, especially when the gallbladder is infected, contains several stones, or may harbor malignancy. Therefore, we made use of a simple surgical glove with a long pursestring suture surrounding the opening to collect the specimen. This method proved to be simple and quite convenient, with the needed materials readily available. It can collect the spilled stones within the abdominal cavity as well as the gallbladder and can transport these stones out of the abdominal cavity with ease and safety. It also protects the specimen in contact with the wound and cuts short the operating time. The technique and advantages are described.

Epithelial desquamation in asthma: artifact or pathology?

To determine whether the denudation of the bronchial epithelium observed in endobronchial biopsies from asthmatic subjects is a true pathologic feature or an artifact of tissue sampling, we analyzed epithelial integrity in bronchial biopsies from 14 subjects with mild and moderate asthma and 12 healthy subjects. In each subject, 4 to 8 bronchial biopsies were taken from large airways during bronchoscopy, fixed in 4% paraformaldehyde, embedded in glycomethacrylate, cut into 2-microM sections, and stained with toluidine blue. A x4 image of each biopsy was copied to a computer file using a video camera, and lines were drawn and measured along the basement membrane underlying areas completely denuded of overlying epithelium, areas covered by a single layer of basal cells, and areas of intact epithelium. We found that the percentage of basement membrane that was denuded of epithelium was similar in the healthy and asthmatic subjects (14.8 +/- 11.8 versus 11.4 +/- 9.8% respectively, p = 0.38); the percentage of basement membrane that was covered by a single layer of basal cells was also similar in the two groups (46.4 +/- 11.0 versus 54.5 +/- 9.8%, respectively, p = 0. 11). In the asthmatic subjects, we found no significant correlation between the percentage of basement membrane covered by denuded epithelium or by a single layer of basal cells and the FEV(1) percentage of predicted or the PC(20) methacholine. We conclude that denudation of bronchial epithelium in endobronchial biopsies from asthmatic subjects with stable mild and moderate disease is an artifact of tissue sampling and is not a true pathologic feature of the disease, and that the extent of airway epithelial denudation is not correlated with the severity of airway narrowing or the severity of bronchial hyperresponsiveness.

Laparosopic removal of large gastric phytobezoars

Large gastric bezoars are difficult to remove endoscopically. A 78-year-old man presenting with abdominal pain and loss of appetite for 4 months was admitted and evaluated. Gastroscopy disclosed two large phytobezoars within the stomach. Laparoscopic removal was undertaken. The bezoars were removed via a gastrotomy using the three-trocar technique. They were successfully retrieved from the abdominal cavity using an improvised "endobag" made from a simple surgical glove. Such an endobag presents several advantages; they are easy to make, sterile, economical, readily available, disposable, there is ample space to manipulate the specimen within, and there is minimal risk of contamination throughout the procedure. The authors recommend this approach for the treatment of patients with large gastric bezoars in whom laparotomy is indicated.

Liberal use of a bag made from a surgical glove during laparoscopic surgery for specimens retrieval

Laparoscopic surgery has been gaining wide acceptance in recent years. Tissue removal from the abdominal cavity becomes a paramount issue, especially when the specimen is infected, contains several fragments, or potentially contains a malignancy. Several sophisticated instruments and devices have been designed for this purpose. However, most of these are expensive, difficult to handle, and come in a fixed size. Condoms, glove fingers, and zipper-type plastic bags have been tried also, but with limited success. The authors report use of a simple bag made from a surgical glove to collect specimens; a long purse-string suture surrounds the opening or the base of the glove finger to secure material during retrieval. This method has been found to be simple and convenient, and necessary construction material is readily available. The bag not only protects the specimen from contact with the wound but also cuts short the operating time. The technique and advantages are described.

Predictors of late asthmatic response. Logistic regression and classification tree analyses

To identify predictors of the late asthmatic response (LAR), we reviewed data from 60 asthmatic subjects who had undergone allergen challenge over the past 5 yr (33 females, age 31.4 +/- 6.7 yr [mean +/- SD], FEV(1) 90% +/- 14% predicted). Variables considered likely predictors of LAR included baseline FEV(1), PC(20) methacholine (PC(20)), sputum eosinophil percent, and the decrease in FEV(1) within 20 min of allergen challenge. A LAR (FEV(1) >/= 15% fall between 3 and 7 h after challenge) was documented in 57% of subjects. A variety of logistic regression methods revealed a significant inverse association between LAR and PC(20) (odds ratio [OR] = 0.14 [95% CI = 0.03-0.66]) and a positive association between LAR and the decrease in FEV(1) at 20 min (OR = 1.18 [1.04 -1.33]). Classification tree analysis revealed that a threshold of 0.25 mg/ml for PC(20) was most predictive of LAR; LAR developed in 87% of those with PC(20) </= 0.25 mg/ml (n = 23) and in 38% of those with PC(20) > 0.25 mg/ml (n = 37). Notably, in subjects with PC(20) > 0.25 mg/ml, the incidence of LAR increased from 38% to 57% if the allergen-induced decline in FEV(1) at 20 min was >/= 27%. Surprisingly, baseline FEV(1) and percent eosinophils in induced sputum were not significantly associated with LAR. We conclude that a threshold value of 0.25 mg/ml for PC(20) methacholine is a good predictor of LAR. Measuring the PC(20) methacholine may be useful as a screening method to improve the efficiency of identifying asthmatic subjects with a LAR.

Production of medium-chain-length polyhydroxyalkanoates by high-cell-density cultivation of Pseudomonas putida under phosphorus limitation

High-cell-density fed-batch cultures of Pseudomonas putida were carried out for the production of medium-chain-length polyhydroxyalkanoates (PHAs) using oleic acid as a carbon source. By employing an optimal feeding strategy without the limitation of any nutrient, a high cell concentration of 173 g/L was achieved, but the PHA concentration and PHA content were only 32.3 g/L and 18.7 wt%, respectively. To increase the PHA concentration and content, phosphorus limitation was applied during fed-bath culture by reducing the initial KH(2)PO(4) concentration. When the initial KH(2)PO(4) concentration was reduced to 4 g/L, cell concentration, PHA concentration, and PHA content obtained in 38 h were 141 g/L, 72. 6 g/L, and 51.4 wt%, respectively, resulting in a high productivity of 1.91 g PHA/L per hour.

Low- and high-dose fluticasone propionate in asthma; effects during and after treatment

The dose dependency of the effects of inhaled corticosteroids on markers of asthmatic airway inflammation have not been well studied. There is a need to study the dose/response effects on this inflammation. In order to determine the dose/response effects of fluticasone propionate (FP), 24 asthmatic subjects were randomized to low- (100 microg x day(-1)) or high-dose (1,000 microg x day(-1)) FP for six weeks followed by placebo for 3 weeks. During treatment, the median increase in forced expiratory volume in one second (FEV1)was 12% in the high-dose group (p<0.05) and 10% in the low-dose group (p<0.05) (p>0.05 between groups); the median decrease in the percentage of sputum eosinophils was 93% in the high-dose group (p<0.05) and 46% in the low-dose group (p<0.05) (p>0.05 between groups). Symptoms, salbutamol use, morning peak flow, provocative concentration of methacholine causing a 20% fall in FEV1 (PC20), sputum eosinophil cationic protein concentration and tryptase activity improved significantly in both groups (p<0.05), but only the improvement in salbutamol use was greater in the high-dose group (p<0.05). During the run-out, the improvements in FEV1 and PC20 were rapidly reversed in both groups, but the improvements in peak flow and tryptase activity persisted; the improvement in sputum eosinophil concentration persisted only in the high-dose group (p<0.05). It was concluded that dose/response effects for FP are not easily demonstrable because low-dose FP is quite effective. For most outcomes, the effects of high- and low-dose FP are relatively short-lived after treatment is stopped. This finding raises questions about the extent to which inhaled corticosteroids are disease-modifying in asthma.

Laparoscopic resection of an omental cyst with pedicle torsion

Omental cysts are the least-common variety of all types of intra-abdominal cystic lesions. In the past, transabdominal laparotomy with excision of the cyst was the treatment of choice. With the advent of laparoscopic surgery, it has become possible to resect the cyst without the need for a large incision in the abdomen. We report a case of a 15-year-old girl who underwent diagnostic laparoscopy for recurring abdominal pain of 2 years' duration. The procedure revealed a huge cyst lying above the omentum with its pedicle rising from the greater curvature of the stomach. The pedicle was noted to have twisted eight times in a clockwise direction. The cyst was resected by laparoscopic means using three trocars. The postoperative course was uneventful. As presented in this case, we believe that a laparoscopic approach is an attractive alternative for the management of omental cystic lesions.

Effect of aerosolized anti-IgE (E25) on airway responses to inhaled allergen in asthmatic subjects

Intravenous administration of a humanized monoclonal antibody of IgE (E25) attenuates the early and late phase response to inhaled allergen in allergic asthmatic subjects. To test whether direct delivery of E25 to the airway might have the same effect, we conducted a randomized, double-blind, three group study in 33 subjects with mild allergic asthma (20 to 46 yr of age, 21 men, FEV(1) > 70% predicted). The airway responses to aerosolized allergen were determined at baseline, after 2 and 8 wk of once daily treatment with aerosolized placebo (n = 11), aerosolized E25 1 mg (n = 12), or aerosolized E25 10 mg (n = 10), and after 4 wk of treatment withdrawal. We found that E25 was detectable in the serum during aerosol treatment, although serum IgE did not change significantly in any of the three groups during treatment. In addition, both doses of E25 were no more effective than placebo in attenuating the early phase responses to allergen at both times during treatment. Although aerosolized E25 was generally well tolerated, one subject receiving aerosolized E25 10 mg daily was found to have serum IgG and IgA antibodies to E25. We conclude that aerosol administration of an anti-IgE monoclonal antibody does not inhibit the airway responses to inhaled allergen in allergic asthmatic subjects. We speculate that the observed lack of efficacy may be due to the inability of aerosol route of delivery to result in high enough concentrations of E25 in the tissue compartments surrounding IgE effector cells to neutralize IgE arising from local airway and pulmonary sources and IgE arising from the vascular space. Additionally, the aerosol route of delivery of monoclonal antibodies may be more immunogenic than the parenteral route.

Fractional analysis of sequential induced sputum samples during sputum induction: evidence that different lung compartments are sampled at different time points

BACKGROUND

The effect of the duration of sputum induction on markers of inflammation in induced sputum is unknown, and the optimal duration of sputum induction for research purposes in airway disease is uncertain.

OBJECTIVE

We sought to determine whether the duration of sputum induction influences the cellular or biochemical characteristics of induced sputum.

METHODS

Induced sputum was collected sequentially at 4-minute intervals during a 20-minute sputum induction in 12 subjects with mild and moderate asthma. Each 4-minute sample was collected and analyzed separately for total and differential cell counts and for levels of eosinophil cationic protein, fibrinogen, mucin-like glycoprotein, and surfactant protein SP-A.

RESULTS

The percentages of eosinophils and neutrophils were significantly higher at the beginning of the 20-minute sputum induction than at the end, whereas the percentage of macrophages was significantly lower at the beginning than at the end. In addition, the levels of eosinophil cationic protein and mucin-like glycoprotein were significantly higher at the beginning of the 20-minute induction than at the end, whereas the level of surfactant protein SP-A was significantly lower.

CONCLUSIONS

The duration of sputum induction significantly affects the cellular and biochemical composition of induced sputum in a manner suggesting that large airways are sampled at the beginning of sputum induction, whereas peripheral airways and alveoli are sampled at later time periods. Our data demonstrate the importance of standardizing the duration of sputum induction in clinical research studies, and on the basis of these data, we have chosen 12 minutes as the optimal duration for sputum induction in asthmatic subjects.

Recent advances in polyhydroxyalkanoate production by bacterial fermentation: mini-review

Poly(3-hydroxybutyrate) [P(3HB)] and other polyhydroxyalkanoates (PHAs) have been drawing much attention as biodegradable substitutes for conventional nondegradable plastics. For the economical production of P(3HB), various bacterial strains, either wild-type or recombinant, and new fermentation strategies were developed for the production of P(3HB) with high concentration and productivity. To reduce the cost of carbon substrate, several processes for P(3HB) production from cheap carbon sources were also developed. P(3HB) can now be produced to a content of 80% of cell dry weight with the productivity greater than 4 g/l per h. Fermentation strategy was also developed for the efficient production of medium chain length PHA by high cell density culture. With all these advances, P(3HB) and PHAs can be produced by bacterial fermentation at a cost (ca. $2/kg) similar to that of other biodegradable polymers under development.

Effect of post-induction nutrient feeding strategies on the production of bioadhesive protein in Escherichia coli

The effect of post-induction nutrient feeding strategies on the production of bioadhesive protein using an IPTG inducible expression system in Escherichia coli was investigated. Cells were cultured in an exponential fed-batch mode to the OD600 of ca. 100 (48 gDCW/L) prior to induction. Six different post-induction nutrient feeding strategies (pH-stat, exponential, constant and linear change in feeding rate with three different slopes) were then applied, and bioadhesive protein production was examined. It was found that post-induction cell growth was independent of nutrient feeding rate. However, bioadhesive protein production was significantly affected by post-induction feeding strategies. Linearly changing post-induction feeding rate with a suitable slope allowed production of bioadhesive protein up to 5.3 g/L, which was higher than that obtained by the other post-induction feeding strategies.

Poly-(3-hydroxybutyrate) production from whey by high-density cultivation of recombinant Escherichia coli

Recombinant Escherichia coli strain GCSC 6576, harboring a high-copy-number plasmid containing the Ralstonia eutropha genes for polyhydroxyalkanoate (PHA) synthesis and the E. coli ftsZ gene, was employed to produce poly-(3-hydroxybutyrate) (PHB) from whey, pH-stat fed-batch fermentation, using whey powder as the nutrient feed, produced cellular dry weight and PHB concentrations of 109 g l-1 and 50 g l-1 respectively in 47 h. When concentrated whey solution containing 210 g l-1 lactose was used as the nutrient feed, cellular dry weight and PHB concentrations of 87 g l-1 and 69 g l-1 respectively could be obtained in 49 h by pH-stat fed-batch culture. The PHB content was as high as 80% of the cellular dry weight. These results suggest that cost-effective production of PHB is possible by fed-batch culture of recombinant E. coli using concentrated whey solution as a substrate.

Pilot-scale extraction of PHB from recombinant E. coli by homogenization and centrifugation

A new method of poly-beta-hydroxybutyrate (PHB) extraction from recombinant E. coli is proposed, using homogenization and centrifugation coupled with sodium hypochlorite treatment. The size of PHB granules and cell debris in homogenates was characterised as a function of the number of homogenization passes. Simulation was used to develop the PHB and cell debris fractionation system, enabling numerical examination of the effects of repeated homogenization and centrifuge-feedrate variation. The simulation provided a good prediction of experimental performance. Sodium hypochlorite treatment was necessary to optimise PHB fractionation. A PHB recovery of 80% at a purity of 96.5% was obtained with the final optimised process. Protein and DNA contained in the resultant product were negligible. The developed process holds promise for significantly reducing the recovery cost associated with PHB manufacture.

The leukotriene receptor antagonist zafirlukast inhibits sulfur dioxide-induced bronchoconstriction in patients with asthma

Inhalation of sulfur dioxide (SO2) causes bronchoconstriction in most people with asthma. To examine the role of leukotrienes in this response, the antagonism of SO2-induced bronchoconstriction by a single oral dose of the leukotriene receptor antagonist zafirlukast was assessed in a double-blind, placebo-controlled, two-period crossover trial in 12 subjects with mild-to-moderate asthma. Subjects had bronchial hyperresponsiveness, an FEV1 < or = 70% of predicted, and a positive response to inhaled SO2 (an 8-unit increase in specific airway resistance on inhaling an SO2 concentration of < or = 4 ppm (PC8SRaw). Subjects were treated with zafirlukast (20 mg) or placebo on two treatment days 5 to 14 d apart. Two and 10 hours after treatment, subjects inhaled SO2 (0.25, 0.5, 1.0, 2.0, 4.0, and 8.0 ppm) during eucapnic hyperventilation at 20 L/min. PC8SRaw was determined after each challenge. Blood samples were collected to assess zafirlukast plasma concentrations versus effect. PC8SRaw was significantly higher 2 h after zafirlukast compared with placebo (3.1 versus 1.5 ppm; p = 0.02) and remained higher 10 h after treatment with zafirlukast (2.7 versus 1.9 ppm; p = 0.09). An association was found between zafirlukast plasma concentrations and increases in PC8SRaw 10 h after treatment (p = 0.001). The safety profile of zafirlukast was not clinically different from placebo. A single 20-mg dose of zafirlukast attenuated SO2-induced bronchoconstriction. We conclude that S02-induced bronchoconstriction involves release of leukotrienes and that treatment with zafirlukast attenuates the bronchoconstrictor response.

Centrifugal processing of cell debris and inclusion bodies from recombinant Escherichia coli

The settling characteristics of cell debris and inclusion bodies prior to, and following, fractionation in a disc-stack centrifuge were measured using Cumulative Sedimentation Analysis (CSA) and Centrifugal Disc photoSedimentation (CDS). The impact of centrifuge feedrate and repeated homogenisation on both cell debris and inclusion body collection efficiency was investigated. Increasing the normalised centrifuge feedrate (Q/sigma) from 1.32 x 10(-9) m s-1 to 3.97 x 10(-9) m s-1 leads to a 36% increase in inclusion body paste purity. Purity may also be improved by repeated homogenisation. Increasing the number of homogeniser passes results in smaller cell debris size whilst leaves inclusion body size unaltered. At a normalised centrifuge feedrate of 2.65 x 10(-9) m s-1, increasing the number of homogeniser passes from two (2) to ten (10) improved overall inclusion body paste purity by 58%. Grade-efficiency curves for both the cell debris and inclusion bodies have also been generated in this study. The data are described using an equation developed by Mannweiler (1989) with parameters of k = 0.15-0.16 and n = 2.5-2.6 for inclusion bodies, and k = 0.12-0.14 and n = 2.0-2.2 for cell debris. This is the first accurate experimentally-determined grade efficiency curve for cell debris. Previous studies have simply estimated debris grade efficiency curves using an approximate debris size distribution and grade efficiency curves determined with 'ideal particles' (e.g. spherical PVA particles). The findings of this study may be used to simulate and optimise the centrifugal fractionation of inclusion bodies from cell debris.

Nonprescription bronchodilator medication use in asthma

STUDY OBJECTIVE

Many persons with asthma self-medicate with widely available and potentially hazardous nonprescription medicines. This study assessed the demographic and clinical covariates of self-treatment with over-the-counter asthma medications (OTCs).

DESIGN AND SETTING

We conducted an analytical investigation using questionnaires and measures of lung function, comparing OTC and prescription medication users. We recruited adults with asthma by public advertisement.

SUBJECTS

We studied 22 exclusive prescription asthma medication users, 15 exclusive OTC users, and 13 other subjects who combined prescription medication use with self-treatment with asthma OTCs. All but one OTC user self-medicated with a nonselective, sympathomimetic metered-dose inhaler.

RESULTS

Taking income, access to care, and self-assessed disease severity into account, male gender was strongly associated with exclusive OTC use alone (odds ratio [OR]=8.9, 95% confidence interval [CI]= 1.3 to 61) and mixed OTC-prescription medication use (OR=9.7, 95% CI=1.1 to 83). The covariates of income, access to care, and self-assessed disease severity provided significant additional explanatory power to the model of exclusive OTC use (model chi2 difference 11.3, 5 df, p<0.05). Pulmonary function was similar among OTC and prescription medication users. However, prescription medication users' self-assessed asthma severity (mild compared to more severe) was associated with postbronchodilator reversibility of FEV1 obstruction (6% vs 18% reversibility, p<0.05) while exclusive OTC users' self-assessed severity showed the reverse pattern (19% vs 8%, p=0.2).

CONCLUSION

Asthma education programs attempting to discourage unregulated bronchodilator use should give consideration to this profile of the "asthmatic-at-risk."

Safety of one method of sputum induction in asthmatic subjects

To assess the safety of sputum induction in asthmatic subjects, we conducted a retrospective review of data from 351 sputum inductions in 78 subjects from our institution. The sputum induction protcol consisted of baseline FEV1, pretreatment with albuterol 180 micrograms, postbronchodilator spirometry 15 min later, the induction procedure itself (inhalation of 3% saline for 20 min), and postsputum induction spirometry. We found that sputum induction was usually well tolerated, although some subjects developed wheeze and dyspnea. Overall, 11 of the 78 subjects (14%) had a fall in FEV1 of > or = 20% from the postbronchodilator baseline ("excessive bronchoconstriction") during their first sputum induction (range: -20 to -69%); no subject developed refractory bronchoconstriction requiring hospitalization or emergency room treatment. Only one of the 54 subjects (1.9%) with a baseline prebronchodilator FEV1 > 80% had excessive bronchoconstriction, whereas 10 of the 24 subjects (42%) whose baseline FEV1 was < or = 80% predicted did so. The change in FEV1 during sputum induction was significantly correlated with the baseline prebronchodilator FEV1% predicted, the baseline postbronchodilator FEV1% predicted, the PC20 for methacholine, and the percentage of eosinophils in induced sputum. We conclude that 180 micrograms albuterol does not prevent excessive bronchoconstriction in all asthmatic subjects undergoing sputum induction, especially in asthmatic subjects with a low baseline FEV1. Pulmonary function should be monitored regularly during sputum induction in asthmatic subjects to monitor for excessive bronchoconstriction.

The effect of an anti-IgE monoclonal antibody on the early- and late-phase responses to allergen inhalation in asthmatic subjects

A humanized murine monoclonal antibody directed to the Fc epsilonR1-binding domain of human IgE (rhuMAb-E25) has been shown to inhibit the binding of IgE to mast cells without provoking mast cell activation. To examine the effects of neutralizing IgE on allergic airway responses, we assessed the effects of 9 wk of treatment with rhuMAb-E25 in a parallel group, randomized, double-blind, placebo-controlled study of 19 allergic asthmatic subjects. We found that treatment with rhuMAb-E25 reduced serum IgE, increased the dose of allergen needed to provoke an early asthmatic response, reduced the mean maximal fall in FEV1 during the early response (30 +/- 10% at baseline to 18.8 +/- 8%, versus 33 +/- 8% at baseline to 34 +/- 4% after placebo; p = 0.01), and reduced the mean maximal fall in FEV1 during the late response (24 +/- 20% at baseline to 9 +/- 10% versus 20 +/- 17% at baseline to 18 +/- 17% after placebo; p = 0.047). We conclude that an anti-IgE monoclonal antibody, which inhibits binding of IgE to its receptor, suppresses the early- and late-phase responses to inhaled allergen in allergic asthmatic subjects. Targeting IgE with rhuMAb-E25 might be a useful treatment for allergic asthma.

Similar RANTES levels in healthy and asthmatic airways by immunoassay and in situ hybridization

To determine if RANTES expression is unregulated in the airways of asthmatic subjects, we performed bronchial mucosal biopsies and airway lavage in seven atopic asthmatic subjects and eight healthy subjects. Immunohistochemistry was used to reveal RANTES protein expression in the airway biopsies. An ELISA was used to quantitate RANTES in lavage. In three subjects in each group, we also used in situ hybridization to reveal mRNA for RANTES in airway biopsies. We found that the mean (+/- SD) percent expression for RANTES in the epithelium and submucosa was 26 +/- 9% and 26 +/- 10% in the asthmatic and healthy tissue samples, respectively. RANTES mRNA was demonstrable in the bronchial mucosa of both healthy and asthmatic subjects, predominantly in the epithelial cells but also in the submucosa. We also found that there was no significant difference in the median RANTES concentrations between the groups (healthy: 2.9 pg/ml [range: 0.0 to 28.7 pg/ml]; asthma: 1.8 pg/ml [range: 0.0 to 82.1 pg/ml], p > 0.05) despite a trend for higher concentrations of eosinophil cationic protein (ECP) in the asthmatic group (p = 0.08). In summary, this study confirms that cells in airway mucosal tissue produce RANTES but that the level of production in mild stable asthma is not different from that of healthy control subjects.

Comparison of two methods of collecting induced sputum in asthmatic subjects

The method that we have previously reported for sputum induction involves collecting the entire expectorate produced over a 20 min inhalation of 3% saline aerosol. This method presents the potential disadvantage of a considerable and variable salivary contribution to the induced sputum sample. In this study, we examined whether separate collection of saliva and sputum represents a better method for collecting induced sputum during sputum induction. In 11 stable asthmatics, we compared the volume, total and differential cell counts, and eosinophil cationic protein (ECP) levels in four induced sputum samples, two performed using our previous method (Method A) and two using another method (Method B) in which subjects spit saliva into one container before coughing sputum into another. We found that the volume of sputum obtained with Method B was lower than that obtained with Method A (6.16 +/- 0.61 vs 20.1 +/- 2.7 mL; p = 0.003), as was the percentage of squamous cells (34 +/- 4 vs 47 +/- 6; p = 0.023). In addition, the ECP levels in samples collected by Method B were higher (261 +/- 42 vs 145 +/- 26 ng.mL-1; p = 0.01). The differential counts of nonsquamous cells were similar except for the percentage of neutrophils, which was lower in Method B (37 +/- 4 vs 50 +/- 5%; p = 0.019). The repeatability of measurements of eosinophil percentages and of ECP levels was similar for the two methods. We conclude that separate collection of saliva and sputum yields induced sputum samples with reduced amounts of saliva and is, therefore, a better method for collecting induced sputum.

Centrifugal recovery and dissolution of recombinant Gly-IGF-II inclusion-bodies: the impact of feedrate and re-centrifugation on protein yield

The impact of centrifuge feedrate and multiple centrifuge passes on protein yield following recombinant Gly-Insulin-like Growth Factor II (Gly-IGF-II) inclusion-body dissolution has been investigated. Altering centrifuge feedrate did not significantly improve the overall protein yield following dissolution. Improved centrifuge recovery at a low feedrate was offset by poorer inclusion body paste purity. This reduced purity resulted in a significant loss of protein during inclusion-body dissolution due to proteolysis. Multiple centrifuge passes improved the inclusion-body paste purity. This resulted in a net improvement in the overall protein yield following dissolution. This work demonstrates that a strong interaction exists between centrifuge performance and inclusion-body dissolution for protease-sensitive products such as Gly-IGF-II.

Effect of an NK1 receptor antagonist (CP-99,994) on hypertonic saline-induced bronchoconstriction and cough in male asthmatic subjects

To investigate the role of NK1 receptors in the pathogenesis of bronchoconstriction and cough in asthma, we performed a randomized, double-blind, crossover study on the effects of a selective non-peptide tachykinin NK1 receptor antagonist (CP-99,994) on baseline measures of lung function and on hypertonic saline-induced bronchoconstriction and cough in 14 male subjects with mild asthma. CP-99,994 (250 micrograms/2 hours) and placebo were administered intravenously in 2-h infusions during consecutive visits 5 to 7 d apart. Specific airway resistance (SRaw) was measured and spirometry was performed at baseline and at 35 and 60 min. Next, hypertonic saline challenge was performed by delivering 10 breaths of saline of increasing concentration (0.9 to 7% in 1% increments at 5-min intervals) via an ultrasonic nebulizer until SRaw increased from baseline by 200% or 20 units, whichever was greater. Throughout the challenge cough was counted from a taped record made from two microphones placed close to the subject's larynx. We found that CP-99,994 did not significantly affect SRaw or spirometric measures of lung function during the first hour of infusion. Although CP-99,994 infusion markedly attenuated the bronchoconstrictor response to the saline challenge in two subjects, it did not significantly decrease the area under curves obtained for SRaw and cough during saline challenge for the group as a whole (p = 0.9 for SRaw;p = 0.8 for cough). We conclude that administration of 250 micrograms/kg of CP-99,994 over 2 h does not significantly inhibit hypertonic saline-induced bronchoconstriction or cough in subjects with mild asthma and does not have acute bronchodilator activity in these subjects.

Analysis of induced sputum after air and ozone exposures in healthy subjects

Exposure of healthy subjects to ozone is associated with increases in cellular and biochemical markers of inflammation in bronchoalveolar lavage fluid. To determine if analysis of induced sputum might similarly reveal the pulmonary inflammatory effects of ozone exposure, we performed cellular and biochemical analysis of induced sputum collected 4 hr after air and ozone (0.4 ppm for 2 hr) exposures from 10 healthy subjects (age 30.0 +/- 5.0 years; 5 females) in a randomized crossover study in which exposures were separated by 2 weeks. We found that the total number of nonsquamous cells was significantly higher after ozone exposure than after air exposure (7.4 vs 3.9 x 10(5)/ml, P < 0.05) as was the percentage of the nonsquamous cells that were neutrophils (80.0 +/- 7.0% vs 51.0 +/- 20.0%, P < 0.05) and the levels of myeloperoxidase in the sputum fluid phase (1.6 +/- 0.6 vs 1.3 +/- 0.6 microg/ml, P < 0.05). In addition, IL-6 and IL-8 levels were higher after ozone than after air exposures, but not significantly so (44.5 +/- 32.4 pg/ml vs 26.8 +/- 30.7 pg/ml, P = 0.11; 1.5 +/- 0.5 ng/ml vs 1.1 +/- 0.6 ng/ml, P = 0.09). Mucin-like glycoprotein levels were also not significantly different between exposures (1.6 +/- 0.9 mg/ml vs 1.3 +/- 1.0 mg/ml, P = 0.26). We conclude that analysis of induced sputum is a useful noninvasive method for studying the pulmonary response to ozone exposure in healthy subjects.

Photoactivatable antisense DNA: suppression of ampicillin resistance in normally resistant Escherichia coli

Antisense oligodeoxyribonucleotides complementary to a segment of the beta-lactamase gene and containing psoralen monoadducts at specific sites were examined for their ability to make normally resistant bacteria sensitive to ampicillin. Irradiation of oligonucleotides and psoralens with long-wavelength ultraviolet radiation (380-400 nm) produced monoadducted antisense molecules. High-performance liquid chromatography was used to purify microgram quantities of photoactivatable antisense DNA. Escherichia coli transformed with a plasmid containing the gene for beta-lactamase were used to test a series of oligonucleotides containing psoralen monoadducts after additional exposure to the photoactivating effects of long-wavelength ultraviolet radiation (320-400 nm). Normally resistant bacteria treated with this photoactivatable form of antisense DNA (0.4 microM) were specifically sensitized to ampicillin. The reduction in colony formation ranged from 31 to 79% in comparison to control oligonucleotides which did not contain photoactivatable monoadduct moieties. Bacteria treated in a similar manner but in the presence of tetracycline instead of ampicillin were not affected. The activity of beta-galactosidase, whose gene is located on the same plasmid as beta-lactamase, was not affected.

Risk management. Recommendations for the freestanding oncology center. Part two

Risk management is an active ongoing process for identification and management of possible losses. It is no longer possible, in this day of escalating numbers of suits and escalating dollar amounts for damages, to solely manage this by transfer of liability through insurance. An active program, in order to reduce the potential for liability, needs to be implemented and needs to be continued on an active ongoing basis, even in the freestanding radiation oncology center. This will require expenditure of time and dollars for periodic review by consultants, but will pay handsome rewards by reducing the potential for loss.

Defining the binding site of Xenopus transcription factor IIIA on 5S RNA using truncated and chimeric 5S RNA molecules

The interaction of TFIIIA with deletion fragments of Xenopus 5S RNA has been quantified using a nitrocellulose filter binding assay. TFIIIA binding was found to be more sensitive to the deletion of nucleotides from the 5' terminus of the 5S RNA as opposed to the 3' terminus. These effects have been correlated to the changes in RNA secondary structure resulting from the deletions. Nucleotides 11-108 of the intact 5S RNA provide the necessary sequence and conformational information required for the binding of TFIIIA. Synthetic 5S RNA genes have been constructed so that in vitro transcription with T7 RNA polymerase yields mature 5S RNA. The transcription factor has a higher affinity for somatic vs. oocyte 5S RNA, similar to the differential affinity of TFIIIA for the two genes. Binding studies with chimeric 5S RNA molecules indicated that the increased binding strength of somatic 5S RNA is conferred by nucleotide substitutions in the 5' half of the molecule.

Penicillinase-producing Neisseria gonorrhoeae: epidemiology, antimicrobial susceptibility and plasmid types

Between 1976 and 1984 204 infections by penicillinase-producing Neisseria gonorrhoeae (PPNG) were seen in the Whitechapel Clinic. In 1984 PPNG were isolated from 4.7% of all patients attending with gonorrhoea. Three infections were homosexually acquired; 140 infections (68%) were acquired in the U.K. Strains that were tested were fully sensitive to spectinomycin (190), cefuroxime (177), kanamycin (170), amoxycillin combined with clavulanic acid (24) and rosoxacin (18). Of 135 strains 61% were resistant to co-trimoxazole, 69% of 169 to tetracycline (MIC greater than or equal to I mg/l) and 32% of 75 to streptomycin. Of 109 strains subjected to plasmid typing, 72(66%) were Asian strains. Of these, 55 (50% of the total) were without and 17 (16% of the total) possessed the 24.5 Mdal transfer plasmid; 27 (25%) were African strains without and 10 (9%) with the transfer plasmid. Of the Asian strains 10 were acquired in Africa. All four plasmid-containing strains are now endemic in the U.K. On the basis of the sensitivity tests, spectinomycin, cefuroxime and kanamycin should be effective in treatment, but not co-trimoxazole and tetracycline.

Phase I pilot study on fast neutron teletherapy for advanced carcinomas of the head and neck region. Final report on local control rate and survival

A final report is presented on the local control rate and length of survival for 100 patients with advanced squamous cell carcinomas of the head and neck region who received fast neutron teletherapy at the University of Washington during the period 1973 through 1977. Sixty-two patients were treated with neutrons alone and 38 were treated with a combination of neutrons and photons as part of a mixed beam fractionation scheme. The overall initial complete remission rate was 68% for the mixed beam group and 44% for the group treated with neutrons alone. Initial complete remission rates for the two groups of patients are given as a function of T-stage and N-stage and acturarial curves are presented which show the time course of local control and survival for the two treatment groups. For T3 and T4 lesions the initial complete remission rate appears to be greater using the mixed beam form of treatment than using neutrons alone. Treatment to high-dose levels using neutrons alone gave rise to significantly greater morbidity--both acute and late effects--than resulted from the mixed beam form of treatment. Local control rates and survival rates are compared with similar groups of patients treated with neutrons at other institutions.