394
(eg, 4 h after a dose of 1-5 mg/kg=8-8 [2’9] umol/1, compared with 12-4 [8’5] J.UTIol/1 4 h after 3 mg/kg dose). When the ELF alAT levels reached 8 nmol/1 there was complete inhibition of ELF neutrophil elastase activity in almost all ELF samples and anti-neutrophil elastase capacity returned (fig 2). Western blot analysis with antibodies against alAT and neutrophil elastase showed that alAT in pretreatment ELF was either complexed with neutrophil elastase or cleaved, whereas after alAT alAT aerosolised
the ELF contained free alAT and greater of alAT complexed to neutrophil elastase (fig 2). Exposure of neutrophils to cystic fibrosis respiratory ELF caused pronounced impairment of pseudomonas killing, a phenomenon directly related to the presence of active neutrophil elastase in the ELF (fig 3). Whereas neutrophils exposed to neutrophil elastase in vitro were no longer effective in killing pseudomonas, added alAT prevented this adverse effect. Neutrophils exposed to pretreatment ELF from cystic fibrosis patients did not kill effectively, whereas neutrophils exposed to the same ELF plus added alAT retained the ability to kill pseudomonas. Posttreatment ELF from cystic fibrosis patients did not impair killing of pseudomonas.
treatment amounts
Neutrophil elastase, a powerful protease released by or effete neutrophils, destroys the extracellular modifies matrix, airway epithelial cells, and interferes with host defence .3,4,6,7 In this 1-week, preliminary respiratory we aerosol delivery of alAT to the showed that study, is sufficient to raise alAT surface respiratory epithelial levels in the ELF two to three times above baseline, suppress the active neutrophil elastase, increase the anti-neutrophil elastase capacity and the amount of alAT/neutrophil elastase complexes, and reverse the ability of respiratory ELF to interfere with neutrophil killing of pseudomonas. These results suggest that this treatment might effectively prevent damage to the normal respiratory tissues by neutrophil elastase and augment host defence on the respiratory epithelial surface, thus potentially reversing a major problem in cystic fibrosis. The results are sufficiently convincing to support controlled clinical trials of alAT and other anti-neutrophil elastases. activated
We thank Chin-Shyan Chu for help with these studies and the Cystic Fibrosis Foundation for support. P. B. was supported by the University Children’s Hospital, Bem, Switzerland.
REFERENCES 1. Boat
TF, Welsh MJ, Beaudet AL. Cystic fibrosis. In: Scriver CR, Beaudet AL, Sly WS, Valle D, eds. The metabolic basis of inherited disease, 6th ed. New York: McGraw-Hill, 1989: 2649-80. 2. Suter S. The imbalance between granulocyte neutral proteases and antiproteases in bronchial secretions from patients with cystic fibrosis. In: Høiby N, Pederson SS, Shand GH, Doring G, Holder IA, eds. Pseudomonas aeruginosa infection. Antibiotic Chemotherapy. Basel: Karger, 1989: 158-68. 3. Berger M, Soerensen RJ, Tosi MF, Dearborn DG, Döring G. Complement receptor expression on neutrophils at an inflammatory site, the pseudomonas infected lung in cystic fibrosis. J Clin Invest 1989; 84: 1302-13. 4. Fick RB, Naegel GP, Squier S, Wood RE, Gee JBL, Reynolds HY. Proteins of the cystic fibrosis respiratory tract: fragmented immunoglobulin G opsonic antibody causing defective opsonophagocytosis. J Clin Invest 1984; 74: 236-48. 5. Wewers MD, Casolaro AM, Sellers SE, et al. Replacement therapy for alpha1-antirypsin deficiency associated with emphysema. N Engl J Med 1987; 316: 1055-62. 6.
Lucey EC, Stone PJ, Christensen TG, Breuer R, Snider GL. An 18-month study of the effects on hamster lungs of intratracheally administered human neutrophil elastase. Exp Lung Res 1988; 14: 671-86.
R, Christensen TG, Niles RM, Stone PJ, Snider GL. Human neutrophil elastase causes glycoconjugate release from the epithelial cell surfaces of hamster trachea in organ culture. Am Rev Respir Dis 1989;
7. Breuer
139: 779-82.
ADDRESSES: Pulmonary Branch, National Heart, Lung, and Blood Institute (N. G. McElvaney, MD, R. C. Hubbard, MD, P Birrer, MD, R G. Crystal, MD); Pediatric Metabolism Branch, National Institute of Diabetes and Digestive and Kidney Diseases (M. S Chernick, MD); and Laboratory of Clinical Investigation, National Institute of Allergy and Infectious Diseases (M M. Frank, MD*), National Institutes of Health, Bethesda, Maryland; and Division of Gastroenterology and Cystic Fibrosis, Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA (D B. Caplan, MD) *Present address: Department of Pediatrics, Duke University, Durham, North Carolina. Correspondence to Dr R. G. Crystal, Building 10, Room 6DO3, National Institutes of Health, Bethesda, Maryland 20892, USA
Pulse oximetry during apparent tonic-clonic seizures
A pulse oximeter was used to monitor arterial oxygen saturations in 11 patients during apparent tonicclonic seizures. 8 had a clinical diagnosis of genuine fits, 6 of whom showed striking falls in oxygen saturation during the seizures. 3 had a clinical diagnosis of pseudoseizures, none of whom had hypoxia during these episodes. Pulse oximetry during apparent tonic-clonic seizures may help to identify patients with low arterial oxygen tension who need immediate intervention.
Pulse
oximetry
is
a
widely available, rapid,
and
non-
invasive technique by which to monitor arterial oxygen saturation. Haemoglobin absorbs more red light than infra-red wavelengths, whereas for oxyhaemoglobin these ratios are reversed. The pulse oximeter sensor measures the amount of red and infra-red light transmitted from a standard light source across a narrow vascular bed (eg, earlobe or finger tip), and from these readings calculates the ratios absorbed and hence the percentage of oxygensaturated haemoglobin. Only pulsatile changes in the ratio are measured, which enables differentiation between arterial and capillary/venous blood. During tonic-clonic fits the limb muscles are most obviously involved in tetanic contraction, but respiratory muscles are also affected, which may lead to poor ventilation, hypoxaemia, and cyanosis, even when upper airway patency is maintained, with the risk of cerebral hypoxia.1 Seizures are commonly encountered in accident and emergency departments, but not all represent genuine fits. Accurate differentiation of genuine and hysterical seizures may be very difficult and empirical use of repeated doses of anticonvulsant drugs may lead to partial anaesthesia of hysterical patients, again with the risk of respiratory depression and cerebral hypoxia. A reproducible and reliable method to differentiate between genuine and hysterical seizures, and to indicate the degree of respiratory embarrassment caused during a seizure, would be helpful. We set out to measure arterial oxygen saturations during true tonic-clonic seizures and hysterical pseudoseizures to determine
395
fits or pseudoseizures, recognition that they are not in imminent danger of hypoxic cerebral damage may allow supportive treatment only to be given while the diagnosis is re-evaluated, before administration of anticonvulsants and the attendant risk of unnecessary sedation. However, it must be emphasised that some patients have normal pulse oximetry readings during true tonic-clonic fits and the technique is not diagnostic of pseudoseizures and should not be used to replace clinical judgment. Nevertheless, use of pulse oximetry may also give a useful early indication of hypoxia from airway obstruction, ventilatory muscle
incoordination, or iatrogenic respiratory depression during
genuine fits or pseudoseizures. REFERENCE 1. Sadeh
M, Goldhammer Y, Kuritsky A. Postictal blindness in adults.
J Neurol Neurosurg Psychiatry 1983; 46:
Arterial oxygen saturations in patients with genuine fits (———)) and pseudoseizures (---).
Left= before/after episode; right=during "fit". whether these correlated with overall clinical state or the apparent
validity of the fit. All patients over the age of 16
who had apparent tonic-clonic seizures while in the accident and emergency departments were included in the study. A pulse oximeter (’Lifestat 1600’, Physio Control, Basingstoke, UK) was attached to all patients who were or who had been fitting on arrival. Oxygen saturations were recorded during and after first seizures and before, during, and after repeated seizures. The type of fit and the presence or absence of tongue-biting, incontinence, and postictal symptoms were recorded. The clinician’s opinion as to whether the fit was real or hysterical was also recorded. Where possible the patient’s previous medical records were obtained to determine previous signs and symptoms, investigations, diagnosis, and treatment. Ipatients were studied: on review of the clinical signs
and past notes, 8 were considered to have had genuine fits and 3 pseudoseizures. All 3 of the patients with pseudoseizures had previously undergone electroencephalography with no abnormal findings even though 2 had had apparent seizures during the recording. Pulse oximetry showed a striking fall in arterial oxygen saturation during the seizures in 6 of the 8 patients with apparently genuine fits (figure); of the 2 who did not show a fall in oxygen saturation 1 had a focal fit that only involved the right side of the body and the other had nearly normal ventilation despite a generalised convulsion. Overall there was a 14.5% average reduction in arterial oxygen saturation during the seizures in patients with apparently genuine fits, but arterial oxygen saturation returned to normal immediately after the fit in all patients, with no apparent long-term reduction caused by administration of anticonvulsants. None of the 3 patients with pseudoseizures showed a striking fall in arterial oxygen saturation during their apparent seizures. Use of the pulse oximeter during seizures was straightforward: 1 patient with pseudoseizures displaced a finger probe, but use of an ear sensor gave
satisfactory readings. Pulse oximetry during apparent tonic-clonic fits is a straightforward technique that can rapidly identify patients with a lowered arterial oxygen saturation who may be at risk of hypoxic cerebral damage if they are not treated rapidly with airway care, supplementary oxygen, and anticonvulsant therapy. Although patients who do not show a striking fall in arterial oxygen saturation may have genuine
566-69.
ADDRESSES: Accident and Emergency Departments, Royal Preston Hospital, Preston PR2 4HT (H. Marshall, MB, M. CarewMcColl, FRCS) and Hope Hospital, Salford M6 8HD, UK (M. R. James, FRCS). Correspondence to Mr M. R. James, Accident and Emergency Department, Royal Preston Hospital, Preston PR2 4HT, UK.
Lymphoscintigraphy with 13I-labelled epidermal growth factor
We have used 123I-labelled epidermal growth factor (EGF) scans to study 14 patients with advanced cervical cancer. Abnormal lymph node imaging was seen most clearly 6-8 h after the injection and revealed abnormal uptake by pelvic lymph nodes in 11 patients. 4 of these 11 had abnormal computerised tomographic and ultrasound scans; in the other 7 conventional radiology did not confirm the presence of disease. Several malignant neoplasms express high levels of epidermal growth factor receptors (EGFR). EGFR have substantial sequence homology to the v-erb-B oncogene product1 and may indicate more aggressive forms of tumour. We have used radiolabelled monoclonal antibodies to EGFR both to localise and to treat tumours.3,4 One major difficulty with the in vivo administration of antibodies is their slow extravasation to the extravascular and intratumoural compartments.5 An alternative approach would be to use the growth factor itself or its analogues6 rather than antibody to a tumour-associated growth-factor receptor. In many cases of cancer, especially cervical cancer, we need accurate staging so that appropriate therapy can be offered-but this can only be achieved by invasive techniques.7 The aim of this study was to assess whether 123I-labelled EGF can concentrate in lymph-node metastases of squamous cell carcinoma of cervix. 14 patients with cancer of the uterine cervix stage III and IV were selected because of their high probability of lymph node metastasis. After the patient’s informed consent was obtained, the thyroid gland was blocked orally with sodium perchlorate the day before and 3 days after injection of 1231-labelled EGF. Sterile and apyrogenic EGF (ICI) was labelled with 1231 by the iodogen
(eg, 4 h after a dose of 1-5 mg/kg=8-8 [2’9] umol/1, compared with 12-4 [8’5] J.UTIol/1 4 h after 3 mg/kg dose). When the ELF alAT levels reached 8 nmol/1 there was complete inhibition of ELF neutrophil elastase activity in almost all ELF samples and anti-neutrophil elastase capacity returned (fig 2). Western blot analysis with antibodies against alAT and neutrophil elastase showed that alAT in pretreatment ELF was either complexed with neutrophil elastase or cleaved, whereas after alAT alAT aerosolised
the ELF contained free alAT and greater of alAT complexed to neutrophil elastase (fig 2). Exposure of neutrophils to cystic fibrosis respiratory ELF caused pronounced impairment of pseudomonas killing, a phenomenon directly related to the presence of active neutrophil elastase in the ELF (fig 3). Whereas neutrophils exposed to neutrophil elastase in vitro were no longer effective in killing pseudomonas, added alAT prevented this adverse effect. Neutrophils exposed to pretreatment ELF from cystic fibrosis patients did not kill effectively, whereas neutrophils exposed to the same ELF plus added alAT retained the ability to kill pseudomonas. Posttreatment ELF from cystic fibrosis patients did not impair killing of pseudomonas.
treatment amounts
Neutrophil elastase, a powerful protease released by or effete neutrophils, destroys the extracellular modifies matrix, airway epithelial cells, and interferes with host defence .3,4,6,7 In this 1-week, preliminary respiratory we aerosol delivery of alAT to the showed that study, is sufficient to raise alAT surface respiratory epithelial levels in the ELF two to three times above baseline, suppress the active neutrophil elastase, increase the anti-neutrophil elastase capacity and the amount of alAT/neutrophil elastase complexes, and reverse the ability of respiratory ELF to interfere with neutrophil killing of pseudomonas. These results suggest that this treatment might effectively prevent damage to the normal respiratory tissues by neutrophil elastase and augment host defence on the respiratory epithelial surface, thus potentially reversing a major problem in cystic fibrosis. The results are sufficiently convincing to support controlled clinical trials of alAT and other anti-neutrophil elastases. activated
We thank Chin-Shyan Chu for help with these studies and the Cystic Fibrosis Foundation for support. P. B. was supported by the University Children’s Hospital, Bem, Switzerland.
REFERENCES 1. Boat
TF, Welsh MJ, Beaudet AL. Cystic fibrosis. In: Scriver CR, Beaudet AL, Sly WS, Valle D, eds. The metabolic basis of inherited disease, 6th ed. New York: McGraw-Hill, 1989: 2649-80. 2. Suter S. The imbalance between granulocyte neutral proteases and antiproteases in bronchial secretions from patients with cystic fibrosis. In: Høiby N, Pederson SS, Shand GH, Doring G, Holder IA, eds. Pseudomonas aeruginosa infection. Antibiotic Chemotherapy. Basel: Karger, 1989: 158-68. 3. Berger M, Soerensen RJ, Tosi MF, Dearborn DG, Döring G. Complement receptor expression on neutrophils at an inflammatory site, the pseudomonas infected lung in cystic fibrosis. J Clin Invest 1989; 84: 1302-13. 4. Fick RB, Naegel GP, Squier S, Wood RE, Gee JBL, Reynolds HY. Proteins of the cystic fibrosis respiratory tract: fragmented immunoglobulin G opsonic antibody causing defective opsonophagocytosis. J Clin Invest 1984; 74: 236-48. 5. Wewers MD, Casolaro AM, Sellers SE, et al. Replacement therapy for alpha1-antirypsin deficiency associated with emphysema. N Engl J Med 1987; 316: 1055-62. 6.
Lucey EC, Stone PJ, Christensen TG, Breuer R, Snider GL. An 18-month study of the effects on hamster lungs of intratracheally administered human neutrophil elastase. Exp Lung Res 1988; 14: 671-86.
R, Christensen TG, Niles RM, Stone PJ, Snider GL. Human neutrophil elastase causes glycoconjugate release from the epithelial cell surfaces of hamster trachea in organ culture. Am Rev Respir Dis 1989;
7. Breuer
139: 779-82.
ADDRESSES: Pulmonary Branch, National Heart, Lung, and Blood Institute (N. G. McElvaney, MD, R. C. Hubbard, MD, P Birrer, MD, R G. Crystal, MD); Pediatric Metabolism Branch, National Institute of Diabetes and Digestive and Kidney Diseases (M. S Chernick, MD); and Laboratory of Clinical Investigation, National Institute of Allergy and Infectious Diseases (M M. Frank, MD*), National Institutes of Health, Bethesda, Maryland; and Division of Gastroenterology and Cystic Fibrosis, Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA (D B. Caplan, MD) *Present address: Department of Pediatrics, Duke University, Durham, North Carolina. Correspondence to Dr R. G. Crystal, Building 10, Room 6DO3, National Institutes of Health, Bethesda, Maryland 20892, USA
Pulse oximetry during apparent tonic-clonic seizures
A pulse oximeter was used to monitor arterial oxygen saturations in 11 patients during apparent tonicclonic seizures. 8 had a clinical diagnosis of genuine fits, 6 of whom showed striking falls in oxygen saturation during the seizures. 3 had a clinical diagnosis of pseudoseizures, none of whom had hypoxia during these episodes. Pulse oximetry during apparent tonic-clonic seizures may help to identify patients with low arterial oxygen tension who need immediate intervention.
Pulse
oximetry
is
a
widely available, rapid,
and
non-
invasive technique by which to monitor arterial oxygen saturation. Haemoglobin absorbs more red light than infra-red wavelengths, whereas for oxyhaemoglobin these ratios are reversed. The pulse oximeter sensor measures the amount of red and infra-red light transmitted from a standard light source across a narrow vascular bed (eg, earlobe or finger tip), and from these readings calculates the ratios absorbed and hence the percentage of oxygensaturated haemoglobin. Only pulsatile changes in the ratio are measured, which enables differentiation between arterial and capillary/venous blood. During tonic-clonic fits the limb muscles are most obviously involved in tetanic contraction, but respiratory muscles are also affected, which may lead to poor ventilation, hypoxaemia, and cyanosis, even when upper airway patency is maintained, with the risk of cerebral hypoxia.1 Seizures are commonly encountered in accident and emergency departments, but not all represent genuine fits. Accurate differentiation of genuine and hysterical seizures may be very difficult and empirical use of repeated doses of anticonvulsant drugs may lead to partial anaesthesia of hysterical patients, again with the risk of respiratory depression and cerebral hypoxia. A reproducible and reliable method to differentiate between genuine and hysterical seizures, and to indicate the degree of respiratory embarrassment caused during a seizure, would be helpful. We set out to measure arterial oxygen saturations during true tonic-clonic seizures and hysterical pseudoseizures to determine
395
fits or pseudoseizures, recognition that they are not in imminent danger of hypoxic cerebral damage may allow supportive treatment only to be given while the diagnosis is re-evaluated, before administration of anticonvulsants and the attendant risk of unnecessary sedation. However, it must be emphasised that some patients have normal pulse oximetry readings during true tonic-clonic fits and the technique is not diagnostic of pseudoseizures and should not be used to replace clinical judgment. Nevertheless, use of pulse oximetry may also give a useful early indication of hypoxia from airway obstruction, ventilatory muscle
incoordination, or iatrogenic respiratory depression during
genuine fits or pseudoseizures. REFERENCE 1. Sadeh
M, Goldhammer Y, Kuritsky A. Postictal blindness in adults.
J Neurol Neurosurg Psychiatry 1983; 46:
Arterial oxygen saturations in patients with genuine fits (———)) and pseudoseizures (---).
Left= before/after episode; right=during "fit". whether these correlated with overall clinical state or the apparent
validity of the fit. All patients over the age of 16
who had apparent tonic-clonic seizures while in the accident and emergency departments were included in the study. A pulse oximeter (’Lifestat 1600’, Physio Control, Basingstoke, UK) was attached to all patients who were or who had been fitting on arrival. Oxygen saturations were recorded during and after first seizures and before, during, and after repeated seizures. The type of fit and the presence or absence of tongue-biting, incontinence, and postictal symptoms were recorded. The clinician’s opinion as to whether the fit was real or hysterical was also recorded. Where possible the patient’s previous medical records were obtained to determine previous signs and symptoms, investigations, diagnosis, and treatment. Ipatients were studied: on review of the clinical signs
and past notes, 8 were considered to have had genuine fits and 3 pseudoseizures. All 3 of the patients with pseudoseizures had previously undergone electroencephalography with no abnormal findings even though 2 had had apparent seizures during the recording. Pulse oximetry showed a striking fall in arterial oxygen saturation during the seizures in 6 of the 8 patients with apparently genuine fits (figure); of the 2 who did not show a fall in oxygen saturation 1 had a focal fit that only involved the right side of the body and the other had nearly normal ventilation despite a generalised convulsion. Overall there was a 14.5% average reduction in arterial oxygen saturation during the seizures in patients with apparently genuine fits, but arterial oxygen saturation returned to normal immediately after the fit in all patients, with no apparent long-term reduction caused by administration of anticonvulsants. None of the 3 patients with pseudoseizures showed a striking fall in arterial oxygen saturation during their apparent seizures. Use of the pulse oximeter during seizures was straightforward: 1 patient with pseudoseizures displaced a finger probe, but use of an ear sensor gave
satisfactory readings. Pulse oximetry during apparent tonic-clonic fits is a straightforward technique that can rapidly identify patients with a lowered arterial oxygen saturation who may be at risk of hypoxic cerebral damage if they are not treated rapidly with airway care, supplementary oxygen, and anticonvulsant therapy. Although patients who do not show a striking fall in arterial oxygen saturation may have genuine
566-69.
ADDRESSES: Accident and Emergency Departments, Royal Preston Hospital, Preston PR2 4HT (H. Marshall, MB, M. CarewMcColl, FRCS) and Hope Hospital, Salford M6 8HD, UK (M. R. James, FRCS). Correspondence to Mr M. R. James, Accident and Emergency Department, Royal Preston Hospital, Preston PR2 4HT, UK.
Lymphoscintigraphy with 13I-labelled epidermal growth factor
We have used 123I-labelled epidermal growth factor (EGF) scans to study 14 patients with advanced cervical cancer. Abnormal lymph node imaging was seen most clearly 6-8 h after the injection and revealed abnormal uptake by pelvic lymph nodes in 11 patients. 4 of these 11 had abnormal computerised tomographic and ultrasound scans; in the other 7 conventional radiology did not confirm the presence of disease. Several malignant neoplasms express high levels of epidermal growth factor receptors (EGFR). EGFR have substantial sequence homology to the v-erb-B oncogene product1 and may indicate more aggressive forms of tumour. We have used radiolabelled monoclonal antibodies to EGFR both to localise and to treat tumours.3,4 One major difficulty with the in vivo administration of antibodies is their slow extravasation to the extravascular and intratumoural compartments.5 An alternative approach would be to use the growth factor itself or its analogues6 rather than antibody to a tumour-associated growth-factor receptor. In many cases of cancer, especially cervical cancer, we need accurate staging so that appropriate therapy can be offered-but this can only be achieved by invasive techniques.7 The aim of this study was to assess whether 123I-labelled EGF can concentrate in lymph-node metastases of squamous cell carcinoma of cervix. 14 patients with cancer of the uterine cervix stage III and IV were selected because of their high probability of lymph node metastasis. After the patient’s informed consent was obtained, the thyroid gland was blocked orally with sodium perchlorate the day before and 3 days after injection of 1231-labelled EGF. Sterile and apyrogenic EGF (ICI) was labelled with 1231 by the iodogen
