Changing patterns in academic allergy-immunology

In evaluation of the current Allergy-Immunology (AI) Program of the Department of Medicine at Northwestern University Medical School and in planning for the future, it appeared that our assessment of changes in the AI program since its inception might be of value to other AI academic programs. Further, we might receive suggestions from other academic AI programs, and we request such advice.

Allergen immunotherapy: a long-term perspective

Efficacy of standard IT to reduce medications and symptoms by at least 50% has been demonstrated multiple times. Reports of negative studies of IT deserve only evaluation of why the study design failed to demonstrate efficacy. Emphasis in the US and worldwide should be on education on the appropriate use of allergen IT, improvements in IT therapy, and preparation for the increased demand for allergists-immunologists as Fellowship training programs decline in numbers and individual training slots decrease.

Potential effect of the administration of substance P and allergen therapy on immunoglobulin E-mediated allergic reactions in human subjects

Previously we observed and reported that immunoglobulin E-mediated (IgE-mediated) allergy in rhesus monkeys was decreased by the administration of substance P (SP) and an allergen. We extended these studies to human subjects, giving SP and 1 allergen to subjects with reactivity to more than 1 allergen, using reactivity to a second allergen as a control. SP and an allergen were initially given by aerosol delivery but subsequently were given by injection. The administration of SP and 1 allergen by aerosol delivery or injection resulted in decreased IgE-mediated reactivity to the allergen administered and also to the control allergen. This result occurred in 7 of 8 human subjects. The 2 initial subjects receiving 8 SP and allergen injections had a sharp reduction in their symptoms of ragweed hay fever lasting for 3 years to date. No significant reactions to the injection of SP occurred. Further controlled human research is necessary on the administration of SP and allergen and the mechanisms of action. Unexpected and serendipitous results first observed in rhesus monkeys and reproduced in allergic human subjects provide a new and potential mechanism for control and perhaps obliteration of common IgE-mediated allergies and even more-serious allergic problems.

The decline and fall of Esperanto: lessons for standards committees

In 1887, Polish physician Ludovic Zamenhof introduced Esperanto, a simple, easy-to-learn planned language. His goal was to erase communication barriers between ethnic groups by providing them with a politically neutral, culturally free standard language. His ideas received both praise and condemnation from the leaders of his time. Interest in Esperanto peaked in the 1970s but has since faded somewhat. Despite the logical concept and intellectual appeal of a standard language, Esperanto has not evolved into a dominant worldwide language. Instead, English, with all its idiosyncrasies, is closest to an international lingua franca. Like Zamenhof, standards committees in medical informatics have recognized communication chaos and have tried to establish working models, with mixed results. In some cases, previously shunned proprietary systems have become the standard. A proposed standard, no matter how simple, logical, and well designed, may have difficulty displacing an imperfect but functional "real life" system.

Occlusion contributes to temporal processing differences between crossed and uncrossed stereopsis in random-dot displays

Stereoscopic depth discrimination was investigated in crossed and uncrossed directions using stimuli defined by binocular disparity differences embedded in dynamic random-dot stereograms. Across three experiments, fixation was directed to a point on the display screen (which placed crossed stimuli in front of and uncrossed stimuli behind, the background dots of the stereogram), to a point in front of the display screen (which placed both crossed and uncrossed stimuli in front of the background dots), and to a point behind the display screen (which placed both crossed and uncrossed stimuli behind the background dots). Results showed that depth discrimination was always good when the stimuli appeared in front of the background dots of the stereogram, whereas discrimination was always poor when the stimuli appeared behind the background dots. These results suggest that differences between crossed and uncrossed stereopsis as reported in past research arose, in part, from effects related to occlusion.

The role of the envelope in processing iterated rippled noise

Iterated rippled noise (IRN) is generated by a cascade of delay and add (the gain after the delay is 1.0) or delay and subtract (the gain is -1.0) operations. The delay and add/subtract operations impart a spectral ripple and a temporal regularity to the noise. The waveform fine structure is different in these two conditions, but the envelope can be extremely similar. Four experiments were used to determine conditions in which the processing of IRN stimuli might be mediated by the waveform fine structure or by the envelope. In experiments 1 and 3 listeners discriminated among three stimuli in a single-interval task: IRN stimuli generated with the delay and add operations (g = 1.0), IRN stimuli generated using the delay and subtract operations (g = -1.0), and a flat-spectrum noise stimulus. In experiment 2 the listeners were presented two IRN stimuli that differed in delay (4 vs 6 ms) and a flat-spectrum noise stimulus that was not an IRN stimulus. In experiments 1 and 2 both the envelope and waveform fine structure contained the spectral ripple and temporal regularity. In experiment 3 only the envelope had this spectral and temporal structure. In all experiments discrimination was determined as a function of high-pass filtering the stimuli, and listeners could discriminate between the two IRN stimuli up to frequency regions as high as 4000-6000 Hz. Listeners could discriminate the IRN stimuli from the flat-spectrum noise stimulus at even higher frequencies (as high as 8000 Hz), but these discriminations did not appear to depend on the pitch of the IRN stimuli. A control experiment (fourth experiment) suggests that IRN discriminations in high-frequency regions are probably not due entirely to low-frequency nonlinear distortion products. The results of the paper imply that pitch processing of IRN stimuli is based on the waveform fine structure.

Hypersensitivity pneumonitis due to humidifier disease: seek and ye shall find

STUDY OBJECTIVES

This study reports a classic case of hypersensitivity pneumonitis (HP) with classic histologic changes in lung tissue and the research used to identify the causative antigens.

DESIGN

A patient with clinical, radiographic, pulmonary function abnormalities and a lung biopsy consistent with HP had no identifiable antigen exposure.

SETTING

Evaluation of the patient's activities provided no suggestion of antigen exposure. Her home was evaluated. It was found that her humidifier ran continually without being cleaned but water was added periodically.

MEASUREMENTS

Serologic analysis demonstrated precipitating antibodies against her humidifier water and ten antigens in the hypersensitivity lung disease serologic panel.

CONCLUSION

Removal of the humidifier, cleaning of the house, and a course of prednisone resulted in the return of the patient to a normal state.

Cell-free hemoglobin preserves renal function during normothermic ischemia

INTRODUCTION

The purpose of this study is to determine whether an infusion of polymerized hemoglobin solution is capable of suppressing the tubular damage and loss of renal function normally seen during a clinically relevant period of warm ischemia.

METHODS

Male rats (350-450 g) were randomized to treatment with control (5% human serum albumin, HSA, n = 6) or test solution (9% polymerized hemoglobin, PHB, n = 6). Following a right nephrectomy, the left renal artery was perfused with 4 ml of HSA or PHB at 37 degreesC. The left renal artery was temporarily occluded for 50 min. At 72 h, creatinine (Cr), blood urea nitrogen (BUN), and percentage hemoglobin (Hb) were measured and the kidney was removed. Stained kidney sections were graded for ischemic injury (0-4, 0 = normal and 4 = necrosis of the proximal tubule). All results were expressed as means +/- SEM and statistical analysis was performed by t test.

RESULTS

Treatment with PHB resulted in lower Cr (1.2 +/- 0.23 mg/dl vs 3.26 +/- 0.60 mg/dl, P < 0.01) and BUN (60.5 +/- 12.7 mg/dl vs 151 +/- 20.2 mg/dl, P < 0.01) at 72 h compared to HSA controls. Total hemoglobin was not significantly different at 72 h. The weight of all treated kidneys increased; however, the increase was significantly less in the PHB-treated group (34 +/- 9.1% vs 70 +/- 7. 4%, P < 0.01). PHB-treated kidneys had less evidence of histologic damage compared to those in the HSA group (0.75 +/- 0.11 vs 2.50 +/- 0.64, P < 0.05).

CONCLUSIONS

During normothermic renal ischemia, renal artery infusion of PHB resulted in preservation of renal function and histologic architecture. PHB solutions may be useful in preserving organ function during prolonged periods of in vivo ischemia.

The cyclopean (stereoscopic) barber pole illusion

Across two experiments, this study found that the barber pole illusion (i.e. grating pattern appearing to move in the direction of the long axis of a rectangular aperture) is perceived with stereoscopic (cyclopean) motion. The grating and aperture comprising the barber pole display were created from binocular disparity differences embedded in a dynamic random-dot stereogram or from luminance differences. In Experiment 1, observers viewed a square-wave grating moving through a rectangular aperture of 2:1 or 4:1 aspect ratio and indicated whether the grating appeared to move in a direction perpendicular to its orientation or in the direction of the long axis of the aperture. For both stereoscopic and luminance stimuli equally, the grating appeared to move in the direction of the aperture (i.e. the barber pole illusion) more often with the larger aspect ratio than with the smaller aspect ratio. The condition for which a stereoscopic grating moved through a luminance rectangular aperture was also examined: the grating appeared to move in the direction of the aperture (inter-attribute barber pole illusion). In Experiment 2, observers viewed a square-wave grating moving through a rectangular aperture of 3:1 aspect ratio whose sides were indented in order to change the local direction of motion of the line terminators. For both stereoscopic and luminance stimuli, the grating appeared to move more frequently in a direction perpendicular to its orientation with the indented aperture (i.e. the illusion was diminished). Thus, local velocity signals from moving stereoscopic line terminators play a role in the production of the barber pole illusion similar to that of luminance motion signals. This suggests that the generation and propagation of motion signals at cyclopean levels of vision play a part in the representation of coherently-moving rigid surfaces.

Malignant cough equivalent asthma: definition and case reports

BACKGROUND

Cough equivalent asthma is a cause for chronic cough and usually responds to corticosteroid therapy. Oral corticosteroids are employed in a diagnostic-therapeutic trial and inhaled corticosteroids are employed in maintenance therapy. In certain cases the cough may be especially severe and require escalated doses of oral corticosteroids for initial control. This is labeled malignant cough equivalent asthma.

OBJECTIVE

To define malignant cough equivalent asthma, provide two case reports, and identify features that should alert physicians to consider the possibility of malignant cough equivalent asthma.

CASE REPORTS

We report two patients who presented complaining of chronic cough that was disruptive of sleep and normal activities, and in one patient prompted an emergency room visit and later hospitalization. The patients underwent evaluation with history, physical examination, and laboratory testing as indicated. Other causes for chronic cough were ruled out by appropriate testing, or were treated, and patients did not respond to usual corticosteroid treatment for cough equivalent asthma. These patients were considered to have a more severe form of cough equivalent asthma and did respond to treatment with higher doses of oral corticosteroids.

CONCLUSION

Malignant cough equivalent asthma is a cause of chronic cough that is disruptive to sleep or normal activities, may lead to emergency room visits or hospitalization, and requires escalated doses of oral corticosteroids for initial control.

A computerized reminder for prophylaxis of deep vein thrombosis in surgical patients

OBJECTIVE

To measure the effect of a computerized reminder system on the rate of deep vein thrombosis (DVT) prophylaxis in surgical patients.

DESIGN

A prospective trial to measure change in compliance compared to historic controls.

MEASUREMENTS

LDS Hospital surgeons developed local consensus as to which procedures should have DVT prophylaxis. The historic rate of prophylaxis for the procedures was measured through a database search of patient records. A computerized reminder system was then implemented which utilized an expert knowledge base and a time drive mechanism to flag surgical cases for DVT prophylaxis. For eligible patients, a DVT reminder appeared on the operating room schedule; surgical staff used this as a guide to apply prophylaxis. During the 3 month trial the rate of DVT prophylaxis was remeasured and compared to the pre-intervention rate.

RESULTS

The pre-intervention rate of DVT prophylaxis over a 3 month period was 85.2% (785 of 921 eligible cases). For the 3 months following the introduction of the computerized reminder, compliance with DVT prophylaxis increased to 99.3% (1084 of 1092 eligible cases). The difference between the historic controls and the study subjects was highly significant (p < 0.001).

CONCLUSION

A computerized reminder is an effective method of increasing the rate of DVT prophylaxis in surgical patients.

A case of idiopathic anaphylaxis associated with respiratory infections

BACKGROUND

Anaphylaxis is associated with IgE-mediated reactions to foods, drugs, and other allergens. Exercise-induced anaphylaxis and food plus exercise-induced anaphylaxis have been reported. Anaphylactoid reactions with no mechanisms determined have been described with radiographic contrast media. Idiopathic anaphylaxis by definition is anaphylaxis with no identifiable external allergen or stimulus. In our series of more than 350 patients with idiopathic anaphylaxis, extensive evaluation has failed to identify a cause for the anaphylaxis.

OBJECTIVE

To report a first case of idiopathic anaphylaxis associated with coryzal symptoms.

METHODS

A patient was evaluated for idiopathic anaphylaxis. Appropriate therapy was initiated.

RESULTS

The patient's anaphylactic episodes are related to the occurrence of coryzal symptoms but no clear IgE-mediated mechanism was identified.

CONCLUSION

This is the first reported association of anaphylaxis with an inciting factor of infection.

Ileal microvillar protein villin is tyrosine-phosphorylated and associates with PLC-gamma1. Role of cytoskeletal rearrangement in the carbachol-induced inhibition of ileal NaCl absorption

In ileal absorptive cells, carbachol inhibits NaCl absorption and its component brush border Na+/H+ exchanger, acting via basolateral membrane receptors. This carbachol effect involves (i) activation of brush border phosphatidylinositol 4,5-bisphosphate-specific phospholipase C (PLC) activity and brush border but not basolateral membrane translocation of PLC-gamma1 (Khurana, S., Kreydiyyeh, S., Aronzon, A., Hoogerwerf, W. A., Rhee, S. G., Donowitz, M., and Cohen, M. E. (1996) Biochem. J. 313, 509-518); and (ii) brush border tyrosine kinase(s) because mucosal but not serosal addition of the tyrosine kinase inhibitor genistein prevents the carbachol-induced inhibition of NaCl absorption and brush border Na+/H+ exchange. In the present work we identify a pool of villin (a brush border actin-binding protein) in the microvillus membrane fraction of rabbit ileum; this pool of villin is tyrosine-phosphorylated and associates with brush border membrane PLC-gamma1. Villin is present both in the Triton X-100-soluble and -insoluble fractions of the brush border. The Triton X-100-soluble pool is approximately 4-fold smaller than the brush border pool of villin that is present in the Triton X-100-insoluble fraction. Only the villin present in the Triton X-100-soluble fraction of ileal villus brush border associates with PLC-gamma1 and is tyrosine-phosphorylated. Carbachol increases the tyrosine phosphorylation of villin rapidly (as early as 30 s) and transiently. Carbachol also increases the amount of tyrosine-phosphorylated villin that associates with PLC-gamma1. These studies demonstrate that carbachol effects on NaCl absorption are accompanied by an increase in brush border PLC-gamma1 association with villin and an increase in tyrosine phosphorylation of villin. To study the role of cytoskeletal rearrangement in carbachol-induced inhibition of NaCl absorption, we used the F-actin stabilizing drug jasplakinolide. Jasplakinolide prevents the carbachol inhibition of ileal NaCl absorption. This suggests that F-actin severing is necessary for carbachol to inhibit ileal villus NaCl absorption. Since villin is known to sever actin, these studies suggest a role for villin in the signaling cascade that begins at the basolateral membrane with carbachol binding to its receptor and ends at the apical membrane in inhibition of NaCl absorption.

Airways obstruction in patients with long-term asthma consistent with 'irreversible asthma'

OBJECTIVE

To describe a series of eight patients with long-term asthma and pulmonary function consistent with "end-stage," irreversible obstruction.

DESIGN

Retrospective descriptive analysis of patients with severe asthma.

SETTING

A university-based allergy-immunology service with a large population of corticosteroid-dependent patients with asthma.

PATIENTS

Eight patients with long-standing asthma and apparently irreversible airways obstruction despite long-term oral and inhaled corticosteroid therapy.

MEASUREMENTS

Pulmonary function data, radiographic studies including chest radiograph and high-resolution CT of the chest, and serologic analysis to rule out allergic bronchopulmonary aspergillosis and alpha1-antitrypsin deficiency had been performed as indicated, and these results were obtained through chart review.

RESULTS

The age of the patients ranged from 41 to 58 years, with a mean duration of asthma of 39 years (SD = 12.4 years). No patient had evidence of any other pulmonary disease process. The mean duration of daily or alternate-day oral corticosteroid treatment was 15.8 years (SD=11.8 years). Despite intensive pharmacotherapy, all patients had an FEV1 57% (42+/-12%) with marked small airways disease as reflected in the forced expiratory flow between 25% and 75% of the FVC. Three of the eight patients demonstrated an accelerated decline in FEV1 despite continuous systemic corticosteroids.

CONCLUSIONS

We have described a series of eight patients with long-standing asthma who demonstrate irreversible airways obstruction despite long-term systemic and inhaled corticosteroids. The term "end-stage asthma" or irreversible asthma might be applied to these patients in whom fixed obstruction has occurred in the absence of other pulmonary diseases.

Pediatric idiopathic anaphylaxis: experience with 22 patients

Idiopathic anaphylaxis in the pediatric population is being increasingly recognized, with symptoms (and therefore classifications) the same as those described in adults. We present a series of 22 patients with special attention to considerations relatively unique to the pediatric population. Prednisone, hydroxyzine, and albuterol were used to control symptoms and induce remission. No deaths occurred during treatment. One adolescent who presented with corticosteroid-dependent idiopathic anaphylaxis was diagnosed with undifferentiated somatoform-idiopathic anaphylaxis. Local physician reluctance to participate in management complicated care for some patients.

Direction discrimination of cyclopean (stereoscopic) and luminance motion

This study compared direction discrimination of cyclopean (stereoscopic) and luminance motion involving stimuli equated for effective strength. The stimuli were random-walk cinematogram (RWC) displays whose signal and noise discs were created from binocular disparity differences embedded in a dynamic random-dot stereogram or from luminance differences. Experiment 1 measured global motion detection thresholds for cyclopean and luminance stimuli by manipulating the proportion of signal to noise discs. Detection thresholds for cyclopean motion were about 25% whereas detection thresholds for luminance motion were 5%, thus five times more cyclopean motion events than luminance events were necessary to elicit threshold responding. Experiment 2 measured thresholds for discriminating the direction of cyclopean and luminance motion under conditions of equal stimulus strength by presenting the motion displays at equal multiples of detection threshold. Direction discrimination thresholds (ranging from about 5-30 deg, depending upon conditions) were similar for cyclopean and luminance motion, thus the precision with which the pooling of local motion events in one direction can be discriminated from the pooling of events in a slightly different direction is the same for cyclopean and luminance stimuli. The finding that cyclopean motion information is pooled is consistent with the idea that the direction of cyclopean motion is coded in the responses of a population of directionally selective mechanisms.

Malignant and corticosteroid-dependent idiopathic anaphylaxis: successful responses to ketotifen

BACKGROUND

Malignant idiopathic anaphylaxis refers to the most severe form of idiopathic anaphylaxis where defined episodes of idiopathic anaphylaxis are not controlled when the prednisone is reduced below at least 60 mg every other day or 20 mg daily. Corticosteroid-dependent idiopathic anaphylaxis refers to patients with idiopathic anaphylaxis who require continuous daily or alternate day prednisone at threshold doses for control of idiopathic anaphylaxis. Ketotifen has been reported to help induce remission in some patients with idiopathic anaphylaxis and has steroid sparing effects in other patients with idiopathic anaphylaxis.

METHODS

We present five patients, two with malignant idiopathic anaphylaxis and three with corticosteroid-dependent idiopathic anaphylaxis, who responded to the administration of ketotifen.

RESULTS

All five patients, while receiving ketotifen, had a reduction or resolution of their episodes of idiopathic anaphylaxis and prednisone was tapered and discontinued.

CONCLUSION

Ketotifen is shown to be successful in inducing remission in two patients with malignant idiopathic anaphylaxis and in three additional patients with corticosteroid-dependent idiopathic anaphylaxis. An additional patient with malignant idiopathic anaphylaxis had prednisone stopped after elective hip surgery.

Heart rate change as a function of age, tidal volume and body position when breathing using voluntary cardiorespiratory synchronization

Voluntary cardiorespiratory synchronization (VCRS), where inspiration and expiration follows a fixed number of heart beats, was used to investigate heart rate change (HRC) in 16 subjects (grouped as 20-30 and 46-57 years of age) as a function of age, body position, and respiratory tidal volumes of 500 and 1000 ml. In phase I, the subjects, following a tone, inspired for two heart beats and expired for three beats. In phase II, the older group's breathing pattern was 2/2, 2/3, 3/3, 4/4, 5/5, and 6/6 inspiratory and expiratory heart beats, respectively, per respiratory cycle. Comparing the younger and older groups, we found a statistically significant (p < 0.05) decrease in HRC for beat 1, 2, and 4 of the respiratory cycle in the supine position, and also for beat 2 in the sitting position, but no significant change with tidal volume. The ratio of the younger to older group's beat 2 HRC was 2.54 sitting and 3.54 supine. Increasing the number of beats per respiratory cycle from four to 12 resulted in the HRC growing from 1.8 to 7.5 beats over the respiratory cycle, showing the importance of respiratory rate in measuring HRC. VCRS can easily observe the influence of each phase of the respiratory cycle on the HRC and show the unique phase dependent changes that occur.

Review of trimellitic anhydride (TMA) induced respiratory response

Acid anhydrides such as trimellitic anhydride (TMA) are of interest due to their important industrial uses and to their adverse health effects in exposed populations. Important industrial uses of TMA include the production of epoxy and alkyd resins used to manufacture a variety of coating materials. The adverse health effects are a result of its direct irritant effects on mucosal surfaces in all exposed humans as well as its ability to cause immunologic sensitization in a small proportion of humans. In those individuals who are immunologically sensitized, reexposure to TMA can result in well described immunologic syndromes: asthma-rhinitis, late respiratory systemic syndrome (LRSS), and very rarely pulmonary disease anemia syndrome (PDA). In summary, adverse health effects of TMA are due to its effects as an irritant, an immunologic sensitizer, or a combination of both.

Recurrence of allergic bronchopulmonary aspergillosis in the posttransplant lungs of a cystic fibrosis patient

Cystic fibrosis (CF) is an autosomal recessive disease of exocrine origin. Allergic bronchopulmonary aspergillosis (ABPA) is an immunologic disorder caused by colonization of the airways with Aspergillus fumigatus. A fumigatus has been cultured from posttransplant lungs in CF patients. Colonization of posttransplant lung with Aspergillus is a recognized phenomenon. In this case report, however, we present a patient who developed ABPA both before and after lung transplant. This patient meets the criteria for ABPA based on serologic results. ABPA may be a complication in post-CF lung transplant patients and serologic analysis should be considered when eosinophilia and pulmonary infiltrates or decline in lung function occurs.

A bradykinin antagonist inhibits both bradykinin- and the allergen-induced airway response in primates

Bradykinin is a mediator of bronchoconstriction and may play a role in the development of the asthmatic response after antigen challenge. Our objective was to study the effectiveness of NPC 17731 as a specific bradykinin beta 2-receptor antagonist and as an antagonist of the allergen-induced early phase of asthma. A primate model was used for all studies. Intracutaneous end-point titrations were performed with bradykinin. A shift of the bradykinin end-point titer was seen when NPC 17731 was injected by the intradermal route prior to performing the end-point titration. Using an aerosolized bradykinin or Ascaris suum antigen airway threshold challenge system, inhibition of the bradykinin or Ascaris airway response was evaluated after pretreatment with aerosolized NPC 17731. NPC 17731 proved to be a safe, effective specific bradykinin receptor antagonist in both cutaneous and airway challenges. NPC 17731 was able to inhibit the antigen-induced airway response in the primate. Bradykinin may play a larger role in mediating the early phase of the antigen-induced asthmatic response than previously was appreciated.

Direction-selective coding of stereoscopic (cyclopean) motion

This study employed a selective adaptation paradigm and investigated thresholds for direction discrimination of translational stereoscopic motion (moving binocular disparity information). The stimuli were moving arrays of randomly positioned stereoscopic discs created from disparity embedded in dynamic random-element stereograms. When discrimination thresholds were measured across a range of base directions following adaptation in a fixed direction, discrimination thresholds were maximally elevated 20-30 deg away from adaptation and reduced in the same direction as adaptation. These results are consistent with a distributed-channel model of direction coding and indicate that the direction of stereoscopic motion is encoded by adaptable direction-selective mechanisms similar to those proposed for luminance-defined motion.

Speed discrimination of stereoscopic (cyclopean) motion

This study investigated the degree to which speed of stereoscopic translational motion (i.e. moving binocular disparity information) can be discriminated in a display that minimizes position information. Observers viewed dynamic random-element stereograms depicting arrays of randomly positioned stereoscopic dots that moved bidirectionally. Two tasks were performed: a speed discrimination task and a displacement discrimination task. Across a range of conditions, speed could be discriminated under conditions in which displacement could not. Thus, speed of stereoscopic motion can be discriminated when position information is minimal. This result indicates that stereoscopic motion is sensed in a way that cannot be explained by feature tracking or by inferring the motion from memory of position and time.

Cost-effective management of malignant potentially fatal asthma

Asthma mortality is rising and noncompliance may be a contributing factor to asthma deaths. We have established a comprehensive treatment program for our most severe asthmatic patients, who are also noncompliant. The objective was to evaluate the effect of a treatment protocol for patients with malignant potentially fatal asthma on both clinical outcome and inpatient costs. A retrospective chart review of eight patients diagnosed with malignant potentially fatal asthma was conducted. Patients were initially evaluated in consultation either at Northwestern Memorial Hospital or in the Allergy-Immunology Clinic at Northwestern Medical Faculty Foundation. The patients all met at least one of the criteria for potentially fatal asthma and each patient was noncompliant with medical care, as they did not follow their doctor's instructions, did not keep scheduled appointments, and/or did not take prescribed medications. A treatment program that included regularly schedule visits with the same attending physician and physician in training, patient and family education, 24-hour telephone access, adequate doses of anti-inflammatory medication and psychiatric referral, if indicated, was instituted. The number of admissions to the hospital including intensive care unit admissions and emergency room visits was tabulated, as was the total cost per year per patient for hospital treatment of asthma before and after starting the treatment program. The number of hospitalizations markedly declined, with three of the eight patients requiring no further admissions to the hospital and three additional patients not requiring admission for at least 4 years. There were no fatal events and no further intensive care unit admissions. The mean cost per person per year for in-patient care before intervention was $22,999 +/- $20,639 and the mean postintervention cost per patient per year was $1107 +/- $1618. This was a statistically significant cost savings (P < 0.0017). We developed a comprehensive treatment program that has enabled us to successfully and cost effectively treat patients with malignant potentially fatal asthma.

The effects of time and light exposure on contact and pressure measurements using Fuji prescale film

The search for methods to demonstrate and accurately measure contact area and pressure within human joints has been and remains an active one. Presenssor is a measuring system developed by Fuji Photo Film Co., Ltd. and used in medical applications. The color intensity fades with time and exposure to light. These changes have not been well documented despite the increasing use of Fuji film in biomedical research. These changes in color intensity provide a source of error in the calculated measurements. The known variability of the color density of film exposed to light and air can be measured and predicted. Methods to control and improve the accuracy and reliability of study data are suggested. Film was exposed to three different amounts of pressure and placed into one of four subgroups: exposed to light and taped or not taped, and stored in the dark and taped or not taped. Fading of the color density was seen after only a few hours of exposure to light when the film was left untaped. When the film was taped, a slight darkening was seen. For the best accuracy and reliability, the film should be digitized or analyzed within eight hours of exposure to pressure.

Outpatient management of Stevens-Johnson syndrome: a report of four cases and management strategy

Stevens-Johnson syndrome is a severe form of erythema multiforme with or without bullous lesions. This is a potentially life-threatening condition that has traditionally required hospitalization for optimal management. We report the successful management of four patients who developed this syndrome following administration of antimicrobial agents. In our experience, for individuals with mild to moderate disease, Stevens-Johnson syndrome can be managed with corticosteroids as an outpatient.

Enduring stereoscopic motion aftereffects induced by prolonged adaptation

This study investigated the effects of prolonged adaptation on the recovery of the stereoscopic motion aftereffect (adaptation induced by moving binocular disparity information). The adapting and test stimuli were stereoscopic grating patterns created from disparity, embedded in dynamic random-dot stereograms. Motion aftereffects induced by luminance stimuli were included in the study for comparison. Adaptation duration was either 1, 2, 4, 8, 16, 32 or 64 min and the duration of the ensuing aftereffect was the variable of interest. The results showed that aftereffect duration was proportional to the square root of adaptation duration for both stereoscopic and luminance stimuli; on log-log axes, the relation between aftereffect duration and adaptation duration was a power law with the slope near 0.5 in both cases. For both kinds of stimuli, there was no sign of adaptation saturation even at the longest adaptation duration.

Idiopathic anaphylaxis: a series of 335 cases

BACKGROUND

Idiopathic anaphylaxis is anaphylaxis with no definable etiology and no trigger by exogenous allergens. Initially described in 1978, idiopathic anaphylaxis has been subsequently characterized and treatment protocols have been established.

OBJECTIVE

The demographics and course of 335 patients (225 previously reported) treated with prednisone, hydroxyzine, and albuterol are now reported.

RESULTS

Ages ranged from 5 to 83 years. There were nine new pediatric patients in this series totaling 14 (4.2%). Atopy was common (48%) with 34 new patients with asthma. The duration of symptoms prior to presentation ranged from three days to 27 years. One hundred thirty-two patients with idiopathic anaphylaxis were available for follow-up. Twenty of these are currently receiving prednisone for control of idiopathic anaphylaxis, seven of them as part of their initial therapy, and ten for control of recurrence of symptoms. Three patients required continuous alternate day prednisone for control of symptoms (corticosteroid-dependent idiopathic anaphylaxis). Of the 335 patients, there were no longer any patients with the diagnosis of malignant idiopathic anaphylaxis defined as requiring prednisone, 20 mg daily, or 60 mg every other day, for control of idiopathic anaphylaxis. Of the six patients previously diagnosed with malignant idiopathic anaphylaxis, five no longer required prednisone and one has a decreased prednisone requirement of 20 mg on alternate days. Hospital visits were significantly reduced by the management regimens. There were no fatalities from idiopathic anaphylaxis in this series.

CONCLUSIONS

The incidence of idiopathic anaphylaxis is increasing in our practice with more patients being evaluated each year. During 1104 patient years of observation (the longest period of single patient observation being 24 years), no inciting agent has been found responsible for the anaphylactic symptoms. Prognosis continues to remain good with the majority of patients achieving remission with pharmacotherapy.

Idiopathic anaphylaxis: long-term follow-up, cost, and outlook

To determine the efficacy of oral corticosteroids, antihistamines, and sympathomimetics in treating patients with idiopathic anaphylaxis, the charts of 225 patients diagnosed with idiopathic anaphylaxis from 1971 to 1990 treated at a single center were reviewed. Sixty-one patients (34 females and 27 males) were available for long-term follow-up. Ages ranged from 10 to 68 years with an average of 39 years. Patients with frequent episodes were treated with a protocol of oral corticosteroids, antihistamines, and sympathomimetics. Patients with infrequent episodes were treated for acute episodes only. The number of emergency room visits, hospitalizations, intensive care unit admissions, and length of time in remission were recorded. Sixty-five percent of patients with infrequent episodes and 91% of patients with frequent episodes of idiopathic anaphylaxis went into remission. Significant decreases in emergency room visits occurred for the idiopathic anaphylaxis-generalized-frequent group (P < 0.016), the idiopathic-anaphylaxis-generalized-infrequent group (P < 0.0001), and the idiopathic anaphylaxis-angioedema-infrequent group (P < 0.039). Significant decreases in the number of hospitalizations (P < 0.022) and intensive care unit admissions (P < 0.009) occurred for the idiopathic anaphylaxis-generalized-infrequent and frequent groups, respectively. Overall, an estimated $184 740 was saved with the treatment program, for 546 patient-years. Idiopathic anaphylaxis can be controlled and remission induced in most patients. An estimated $11 million per year can be saved for patients in the USA on the basis of the estimated prevalence in this country.

Basement shower hypersensitivity pneumonitis secondary to Epicoccum nigrum

Two children developed hypersensitivity pneumonitis after extensive exposure to an unventilated basement shower. Commercial precipitin panels were negative. After home inspection, individual mold species were isolated from the household and extracted. Precipitating antibodies to Epicoccum nigrum were found in both children. Resolution of the hypersensitivity pneumonitis occurred with avoidance and glucocorticosteroid therapy. E nigrum is a newly identified etiologic agent for hypersensitivity pneumonitis found in a mold-contaminated home.

Idiopathic anaphylaxis: a purely internal reaction

Episodes are clinically identical to classic anaphylaxis, yet no external allergen or psychological disorder can be identified as the cause of the patient's symptoms and signs. Combinations of a corticosteroid, an H1-histamine receptor blocker, and a sympathomimetic amine are highly effective at inducing control and can often achieve a remission.

An intervention program to reduce the hospitalization cost of asthmatic patients requiring intubation

BACKGROUND

Asthma is the single disease that accounts for the largest proportion of total health care cost in the US.

OBJECTIVE

To analyze whether an asthma management program affected the cost of subsequent asthma care for patients in whom intubation had been necessary.

METHODS

We evaluated patients with asthma who (1) had required intubation for treatment of status asthmaticus; (2) were 45 years old or younger; (3) had regular follow-up visits in our clinic for 1 year after initial evaluation; and (4) had complete medical records 1 year before and 1 year after the intervention for our evaluation. Medical costs of asthma treatment for each patient were determined for 1 year before and 1 year after intervention. The program included patient education, regular outpatient visits, specialist care, and access to the Allergy Immunology emergency call service. The outcome measures were the total cost of care, inpatient hospitalizations, outpatient services, emergency services, and medicine costs.

RESULTS

Nine patients [mean age 19.6 years (SD = 9.9)] fulfilled the criteria (six women and three men). The mean duration of asthma was 14.0 years (SD = 9.7). The mean total cost of care decreased from $43,066 to $4,914 (t = -4.53, P < .001) and inpatient hospitalization costs decreased from $40,253 to $1,926 (t = -4.50, P <.001). There was, however, no significant difference in the mean pre-intervention versus post-intervention cost of emergency services, outpatient services, or medicine costs.

CONCLUSIONS

The intervention--which included education, specialist care, regular outpatient visits, and access to an emergency call service--significantly reduced the cost of asthma care in our population of patients intubated for asthma.

Will operate for food

After spending 15 years in university, Dr. Robert Patterson recently received the right to write FRCSC after his name, and then began to look for gainful employment as a general surgeon. It was a long and frustrating search. He recounts how he finally found work in northern Alberta, and wonders if next year's residents will encounter the same shortage of opportunities that he discovered.

Direction-selective adaptation and simultaneous contrast induced by stereoscopic (cyclopean) motion

Across four experiments, this study investigated direction-specific adaptation and simultaneous contrast induced by moving binocular disparity information (stereoscopic motion). The stimuli were moving arrays of stereoscopic dots created from dynamic random-element stereograms. Experiments 1 and 2 examined the effects of adaptation to motion in a given direction on the apparent direction of test motion. Results showed that the direction of test motion appeared repulsed away from the direction of adapting motion (repulsion aftereffect) by as much as 20 deg or more when directions of adapt and test were similar. Experiment 3 investigated transfer of the repulsion aftereffect across the stereoscopic and luminance domains by employing stereoscopic adapting motion and luminance test motion or vice versa. Results showed that the repulsion aftereffect transferred across the two stimulus domains. Experiment 4 investigated direction-specific contrast by measuring the perceived direction of two stereoscopic arrays presented simultaneously and moving in different directions. Results showed that the directions of the arrays appeared repulsed away from one another when their directions were similar. Taken together, these results suggest that the direction of stereoscopic motion is coded in the activity of directionally selective mechanisms, as is the case for luminance-domain motion. Transfer of the repulsion aftereffect between stereoscopic and luminance domains indicates the two kinds of motion perception are mediated by a common substrate.

Chronic cutaneous bacterial hypersensitivity

Chronic cutaneous bacterial hypersensitivity (CCBH) is a syndrome of recurrent indolent inflammatory lesions that are caused by a hypersensitivity reaction to skin flora. It can cause significant physical and social distress to those affected, who often endure years of nondiagnostic evaluations and ineffective treatments. We report two additional cases of this syndrome. Skin testing demonstrated IgE to bacterial antigens in both patients, and ELISA demonstrated both IgE and IgG to bacterial antigens in one patient. Both patients improved rapidly and dramatically with oral corticosteroid therapy, although they failed to achieve a lasting remission, as had been seen in previous cases. These represent the fourth and fifth reported cases of CCBH. Despite failure to achieve remission, these patients demonstrate the effectiveness of an inexpensive and safe prednisone regimen in controlling this physically and socially destructive disease.

Disparity tuning of the stereoscopic (cyclopean) motion aftereffect

Across five experiments this study investigated the disparity tuning of the stereoscopic motion aftereffect (adaptation from moving retinal disparity). Adapting and test stimuli were moving and stationary stereoscopic grating patterns, respectively, created from dynamic random-dot stereograms. Observers adapted to moving stereoscopic grating patterns presented with a given disparity and viewed stationary test patterns presented with the same or differing disparity to examine whether the motion aftereffect is disparity contingent. Across experiments aftereffect duration was greatest when adapting motion and test pattern both were presented with zero disparity and in the plane of fixation. Aftereffect declined as disparity of adapting motion and/or test pattern increased away from fixation, even under conditions in which depth position of adapt and test was equal. This argues against a relative depth separation explanation of the decline, and instead suggests that the amount of adaptable substrate decreases away from fixation.