Sleep-related breathing in children with mucopolysaccharidosis.

BACKGROUND: The mucopolysaccharidoses (MPSs), a group of genetic lysosomal storage disorders, are associated with significant morbidity. Secondarily to specific associated anatomical abnormalities, MPS is associated with sleep disordered breathing (SDB), specifically obstructive sleep apnoea (OSA) that may confer additional morbidity. Few studies have examined SDB in children with MPS using full polysomnography (PSG) and thus the exact prevalence and severity of SDB is unknown. Further, successful treatments for SDB in this population have not been explored. OBJECTIVES: This study evaluated both SDB and the efficacy of treatments offered to children with MPS using PSG data. PATIENTS AND METHODS: A retrospective chart review was conducted on all children with MPS and a history of suspected OSA who were referred to the Hospital for Sick Children, Toronto. Both baseline and follow up treatment PSG data were analysed. PSG data recorded included obstructive apnoea-hypopnoea index (OAHI) and central apnoea index (CAI). RESULTS: Fourteen patients (10 male) underwent a baseline PSG. Three of 14 children on ERT were excluded from the main analyses. The median (range) baseline parameters of the population (n = 11) were recorded. The age was 5.2 years (0.8-17.8) and the body mass index (BMI) was 19.9 (13.7-22.2). The OAHI was 6.6 (0.0-54.8); the CAI was 0.6 (0.0-2.6). Seven of 11 (64%) had evidence for OSA and 3/7 children were classified as having severe OSA (OAHI > 10). Of these, 5/7 children underwent treatment for OSA with 3/5 children showing a significant reduction in their OAHI. Further, the 2 patients on ERT therapy with OSA were also both successfully treated. CONCLUSIONS: Children with MPS have a high prevalence of significant OSA and thus should be carefully screened for OSA using full polysomnography and treated accordingly.

Magnesium sulfate in the treatment of refractory ventricular fibrillation in the prehospital setting.

OBJECTIVE: To determine if magnesium sulfate (MgSO(4)) improves outcome in cardiac arrest patients initially in ventricular fibrillation (VF). METHODS: Randomized, prospective, double blind, placebo-controlled, multicenter prehospital trial using 2 g of MgSO(4). Eligible patients were non-traumatic cardiac arrest patients (> or =18 years of age) presenting in VF. The protocol included those patients refractory to three electroshocks. Epinephrine and either 2 g of MgSO(4) or placebo (normal saline) were then administered. The primary outcome variable was return of spontaneous circulation (ROSC) in the field and a perfusing pulse on arrival at the ED. Secondary endpoints included admission to the hospital (ADMT) and hospital discharge (DISC). IRB approval was obtained at all participating centers. RESULTS: Total 116 patients (58 MgSO(4), 58 placebo) were enrolled during the period from 4/1992 to 10/96 with 109 available. There were no significant differences between the groups in baseline characteristics and times to cardio pulmonary resuscitation (CPR), advanced life support (ALS), and first defibrillation, except for time to study drug administration. There was no significant differences in ROSC (placebo, 18.5%, and MgSO(4), 25.5%, P=0.38), ADMT (placebo rate=16.7%, MgSO(4)=16.4%, P=1.0) or DISC (placebo rate=3.7%, MgSO(4)=3.6%, P=1.0). CONCLUSIONS: We failed to demonstrate that the administration of 2 g of MgSO(4) to prehospital cardiac arrest patients presenting in VF improves short or long term survival.

Oral antibiotic use without consulting a physician: a survey of ED patients.

The purpose of our study was to determine the extent to which patients use antibiotics without consulting a physician and to examine patient characteristics associated with such oral antibiotic misuse. The study design was a prospective survey. The setting was a suburban, community, emergency department (ED). The participants were a convenience sample of oriented, ED patients who were enrolled during an 8-week period. Subjects provided written answers to standardized questions regarding their use of oral antibiotics over the 12 months preceding their ED visit. Categorical and continuous data were analyzed by chi-square and t-tests respectively. All test were 2-tailed with alpha set at 0.05. One thousand three hundred sixty three subjects were enrolled; 80% were White, 54% were female, 58% had attended college, 85% had a private physician, and 88% had health insurance. The mean age was 45 +/- 19 years. 43% of patients had used oral antibiotics within the past year. Twenty-two percent of patients indicated that their physicians routinely prescribed antibiotics for their cold symptoms. Seventeen percent of patients had taken "left-over" antibiotics without consulting their physician, most commonly for a cough (11%) or sore throat (42%), and much less frequently for urinary tract infection symptoms (0.7%). Women (19% versus 15% men; P =.04) and patients who attended college (19% versus 14% no college; P =.01) were more likely to have taken "left-over" antibiotics. A significant percentage of our ED patients had taken oral antibiotics without consulting a physician for symptoms frequently caused by viruses. Further study is warranted to examine whether local patterns of outpatient self-prescribing affect community oral antibiotic resistance.

The emergency department as a potential site for smoking cessation intervention: a randomized, controlled trial.

OBJECTIVE: To assess the effect of physician counseling and referral on smoking cessation rates and attendance at a smoking cessation program. METHODS: This was a prospective, randomized clinical trial set in a suburban, community teaching hospital emergency department (ED). During study hours, dedicated research associates enrolled consecutive, stable, oriented patients who were smokers. Eligible, consenting patients were randomized to one of two intervention groups. The control group received a two-page "Stop Smoking" pamphlet from the American Heart Association (AHA). Patients in the intervention group were given the AHA pamphlet along with pharmacologic information and standardized counseling by the attending emergency physician, including written and oral referral to a smoking cessation program. The primary outcome measures were telephone contact/attendance at the smoking cessation program by the intervention group and the rate of smoking cessation in both study groups at three months post-ED visit. Categorical data were analyzed by chi-square and Fisher's exact tests. Rank data were analyzed by Mann-Whitney tests and continuous data by t-tests. All tests were two-tailed with alpha set at 0.05. RESULTS: One hundred fifty-two patients were enrolled; 78 were randomized to the intervention group. Nearly 70% of patients (103) were available for telephone follow-up. The study groups were statistically similar with regard to baseline demographic characteristics and the prevalence of moderate or severe nicotine addiction. None of the patients (0%) in the intervention group contacted or attended the smoking cessation program during the study period (95% CI = 0-4%). The percentages of patients who stopped smoking after three months were similar in the two groups [10.4% (5/48) control vs 10.9% (6/55) intervention; p = 1]. CONCLUSION: The authors found no difference in the smoking cessation rates between ED patients who received written material and those who were counseled by emergency physicians. Referral of patients who smoked to a cessation program was unsuccessful.

Do diabetic patients have higher in-hospital complication rates when admitted from the emergency department for possible myocardial ischemia?

OBJECTIVE: To compare in-hospital complication rates for diabetic and nondiabetic patients admitted from the emergency department (ED) for possible myocardial ischemia. METHODS: This was a prospective, observational study of consecutive consenting patients presenting to a suburban university hospital ED during study hours with typical and atypical symptoms consistent with cardiac ischemia. Demographic, historical, and clinical data were recorded by trained research assistants using a standardized, closed-question, data collection instrument. Inpatient records were reviewed by trained data abstractors to ascertain hospital course and occurrence of complications. Final discharge diagnosis of acute myocardial infarction (AMI) was assigned by World Health Organization criteria. Categorical and continuous data were analyzed by chi-square and t-tests, respectively. All tests were two-tailed with alpha set at 0.05. RESULTS: There were 1,543 patients enrolled who did not have complications at initial presentation; 283 were diabetic. The rule-in rate for AMI was 13.8% for nondiabetic patients and 17.7% for diabetic patients (p = 0.09). Times to presentation were similar for nondiabetic vs diabetic patients [248 minutes (95% CI = 231 to 266) vs 235 minutes (95% CI = 202 to 269); p = 0.32]. Nondiabetic patients tended to be younger [56.6 years (95% CI = 55.8 to 57.4) vs 61.6 years (95% CI = 60.2 to 63.1); p = 0.001] and were less likely to be female (34.3% vs 48.1%; p = 0.001). The two groups had similar prevalences for initial electrocardiograms diagnostic for AMI (5.5% vs 7.4%; p = 0.21). There was no significant difference between nondiabetic and diabetic patients for the occurrence of the following complications after admission to the hospital: congestive heart failure (1.3% vs 1.1%, p = 0.77); nonsustained ventricular tachycardia (VT) (1.3% vs 1.2%, p = 0.93); sustained VT (1.2% vs 1.1%, p = 0.85); supraventricular tachycardia (1.7% vs 3.2%, p = 0.12); bradydysrhythmias (1.9% vs 1.1%, p = 0.33); hypotension necessitating the use of pressors (0.9% vs 1.1%, p = 0.76); cardiopulmonary resuscitation (0.2% vs 0.7%, p = 0.10); and death (0.3% vs 0.7%, p = 0.34). One or more complications occurred with similar frequencies for patients in the two groups (6.3% vs 5.7%; p = 0.70). CONCLUSIONS: No statistically significant difference was found in the postadmission complication rates for initially stable diabetic vs nondiabetic patients admitted for possible myocardial ischemia. Based on these results, the presence or absence of diabetes as a comorbid condition does not indicate a need to alter admitting decisions with respect to risk for inpatient complications.

Safety and efficacy of diclofenac ophthalmic solution in the treatment of corneal abrasions.

STUDY OBJECTIVE: To determine whether the use of diclofenac ophthalmic solution is a safe and effective analgesic in the treatment of traumatic corneal abrasions in the emergency department. METHODS: We conducted a prospective, randomized, double-blinded, placebo-controlled clinical trial. Consenting consecutive patients with corneal abrasions who presented to a community-based ED from August through February 1998 were randomly assigned to receive either diclofenac or control vehicle drops. Pain relief was measured using a visual Numeric Pain Intensity Scale (NPIS) before and after treatment. Exclusion criteria were as follows: age younger than 18 years, pregnancy, history of glaucoma, ocular infection, recent eye surgery, other signs of ocular trauma, narcotics within 6 hours, minimal pain (NPIS score <3), and any allergy to diclofenac or nonsteroidal anti-inflammatory drugs. Patients were discharged with study drug or control vehicle solution, a topical antibiotic, oxycodone-acetaminophen as a rescue analgesic, and a pain diary. The outcome measurements were improvement in NPIS score 2 hours after treatment, use of oxycodone-acetaminophen, and occurrence of any adverse effects. RESULTS: Forty-nine patients were enrolled in the study; 25 received diclofenac and 24 received control vehicle drops. Both groups were similar in gender, age, pretreatment pain duration, NPIS score, and analgesic use. There was significantly greater improvement in the 2-hour NPIS score in the diclofenac group (3.1; 95% confidence interval [CI] 2.3 to 4) compared with the control group (1.0; 95% CI 0.1 to 2.0). The difference between the 2 groups was 2.1+/-1.3 (95% CI 0.8 to 3.4). There was a trend toward fewer patients taking rescue oxycodone-acetaminophen in the diclofenac group (20%; 95% CI 4% to 36%) versus the control group (42%; 95% CI 22% to 62%). Other than transient mild stinging, there were no complications associated with diclofenac use. CONCLUSION: Diclofenac ophthalmic solution appears to be a safe and effective analgesic in the treatment of traumatic corneal abrasions in the ED.

Prevalence of smokers and nicotine-addicted patients in a suburban emergency department.

OBJECTIVE: To define the prevalence of smokers and nicotine-addicted patients in a suburban, community ED. METHODS: This was a prospective survey of consecutive ED patients seen in a suburban ED with an annual patient census of 48,000. Medically stable patients aged 18 years or older were eligible for inclusion. Patients were excluded if they had predominantly psychiatric complaints or were critically ill. Patients were queried about their smoking habits by a closed-question survey, which included the previously validated Fagerstrom Test for Nicotine Dependence. The study was conducted during a six-week period, only at times when there were dedicated research associates available to ensure consecutive patient entry. Continuous variables were analyzed by Student's t-tests. Clinical variables were analyzed by chi-square tests. All tests were two-tailed with alpha at 0.05. RESULTS: 1,515 patients comprised the study group. The mean age (+/-SD) was 45.6 (+/-18.9) years; 52% were female, 25% were nonwhite, and 47% were college graduates. There were 317 (21%) smokers. Patients having private physicians were less likely to smoke (18% vs 29%, p = 0.001). Of all smokers, 46% were moderately to severely nicotine-dependent, 69% wanted to quit, and 30% expressed an interest in joining a smoking cessation program. CONCLUSION: A substantial percentage of ED patients smoke, many of them are nicotine-addicted, and the majority would like to quit. Randomized, controlled trials are needed to determine whether interventions by physicians in the ED can have an impact on the smoking habits of these patients.

Droperidol for acute migraine headache.

The use of intramuscular droperidol to treat acute migraine headache has not been previously reported in the emergency medicine literature. It is a promising therapy for migraine. The authors performed a pilot review of all patients receiving droperidol for migraine in our emergency department (ED) to evaluate its efficacy. We used a retrospective case series, in a suburban ED with an annual patient census of 48,000. All patients with a discharge diagnosis of migraine headache who were treated with i.m. droperidol during a consecutive 5-month period in our ED were identified. All patients received droperidol 2.5 mg intramuscular. As per ED protocol, their clinical progress was closely followed and documented at 30 minutes after drug administration (t30). Demographic and clinical variables were recorded on a standardized, closed-question, data collection instrument. The primary outcome measurement was relief of symptoms at t30 to the point that the patient felt well enough to go home without further ED intervention (symptomatic relief). Thirty-seven patients were treated (84% female), with an ED diagnosis of acute migraine with droperidol during the study period. The mean age was 36 +/- 12 years. Analgesics had been used within 24 hours before ED presentation by 62% of patients. At t30, 30 (81%) patients had symptomatic relief, 2 (5%) felt partial relief but required rescue medication, and 5 (14%) had no relief of symptoms. Drowsiness (14%) and mild akathisia (8%) were the only adverse reactions observed following drug administration. Droperidol 2.5 mg intramuscular may be a safe and effective therapy for the ED management of acute migraine headache. Randomized, controlled trials are warranted to further validate the findings of this preliminary study.

Clinical characteristics of diabetic vs nondiabetic patients who "rule-in" for acute myocardial infarction.

OBJECTIVE: To compare the clinical characteristics of diabetic vs nondiabetic patients who present to the ED with acute myocardial infarction (AMI). METHODS: This was a prospective, observational study at a suburban, university hospital ED of patients presenting to the ED during study hours between December 1993 and October 1996 with typical and atypical symptoms consistent with cardiac ischemia. Diabetic and nondiabetic patients with AMI were compared. Demographic, historical, and clinical data were recorded by trained research assistants using a standardized, closed-question, data collection instrument. Final discharge diagnosis of AMI was assigned by WHO criteria. Continuous variables were analyzed by t-tests. Clinical variables were analyzed by chi-square tests. All tests were two-tailed with alpha preset at 0.05. RESULTS: There were 216 patients with AMI during the study period; 51 of these patients (24%) were diabetic. For diabetic vs nondiabetic patients with AMI, there was no significant difference in age (64.0 +/- 13 vs 60.0 +/- 14 years, p = 0.13), female gender (37% vs 26%, p = 0.13), and time to presentation from symptom onset (192 +/- 238 vs 251 +/- 456 minutes, p = 0.41). Hypertension was the only cardiac risk factor significantly more prevalent in diabetic vs nondiabetic patients with AMI (77% vs 50%, OR = 1.54, 95% CI = 1.24 to 1.91, p = 0.001), though elevated cholesterol (48% vs 33%, OR = 1.47, 95% CI = 1.02 to 2.12, p = 0.06) tended to be more prevalent in the diabetic group. There was no statistically significant difference between the two groups in terms of the frequency of chest pain (OR = 1.04, 95% CI = 0.95 to 1.14, p = 0.30), associated symptoms, and diagnostic ECGs (OR = 1.16, 95% CI = 0.76 to 1.79, p = 0.53). CONCLUSION: Diabetic patients with AMI may have similar symptoms upon presentation as do nondiabetic patients with AMI. Of the cardiac risk factors, hypertension is more prevalent in diabetic vs nondiabetic patients with AMI.

The etiology of cardiac arrest in children and young adults: special considerations for ED management.

Children and young adults rarely present to the emergency department (ED) in cardiac arrest. This review examines published series on nontraumatic, cardiac arrest for patients aged 1 to 45 years and discusses the differential diagnosis for cardiovascular collapse. Among the most common entities encountered are cardiac diseases (hypertrophic cardiomyopathy, myocarditis), airway diseases (pneumonia, epiglottitis, and asthma), epilepsy, hemorrhage (gastrointestinal bleeding, ectopic pregnancy), and drug toxicity (tricyclic antidepressants, cocaine). ED management of children and young adults in cardiac arrest requires an understanding of the heterogeneous pathophysiologic mechanisms and etiologies leading to cardiopulmonary dysfunction in these patients. The emergency physician should give particular focus to airway management for toddlers and preadolescents, because respiratory diseases predominate. When treating an adolescent or young adult, the resuscitation team should also consider toxic causes as well as occult hemorrhage. Management considerations unique to this patient population are discussed.

Fibrinolytic therapy in young women with acute myocardial infarction.

STUDY OBJECTIVE: Previous studies found that women with acute myocardial infarction (AMI) receive less aggressive therapy compared with men. We sought to determine the percentage of young women (12 hours after symptom onset) were the most common reasons for ineligibility.

Minor head trauma in anticoagulated patients.

OBJECTIVE: To determine the incidence of clinically significant intracranial injury in the anticoagulated patient suffering minor head trauma without loss of consciousness (LOC) or acute neurologic abnormality. METHODS: A retrospective chart review was performed based on a computerized search of electronic patient records from six community hospital EDs, one of which is a trauma center. Patients taking warfarin who sustained minor head trauma without LOC having no acute neurologic abnormalities treated from January 1994 to January 1996 were identified using a search of electronic ED records. Charts were reviewed for mechanism of injury, physical examination findings of head injury, and concomitant injury. Prothrombin time and head CT results were recorded if obtained. For those patients not receiving a head CT on ED evaluation, telephone follow-up was performed to determine outcome. RESULTS: There were 65 patients meeting inclusion criteria. Thirty-eight patients had prothrombin times obtained, with ranges from 12.0 sec to 30.7 sec. There was no intracranial injury found in any of the 39 patients having a head CT. Additionally, follow-up on the 26 patients who did not undergo CT scanning revealed no evidence of complications related to their head injuries. CONCLUSIONS: The incidence of clinically significant intracranial injury is extremely low in the anticoagulated patient suffering minor blunt head trauma without LOC or acute neurologic abnormality. CT scanning may not be necessary in these patients. Larger prospective studies are needed to confirm these findings.

Performance of two clinical decision rules for knee radiography.

We designed a prospective observational study to attempt to validate two recently described clinical decision rules for knee radiography. Consecutive patients aged > or = 15 yr with acute knee injuries occurring less than 1 wk prior to presentation were included for study. Patients with distracting conditions, open knee injuries, or previous surgery were excluded. Each patient was assessed for 7 historical and 15 physical examination criteria that were recorded on a standardized data collection instrument. Radiographs were ordered at the discretion of the attending physician and were read by two board-certified radiologists. When radiographs were not ordered, structured telephone follow-up was performed after 3 wk. The main outcome parameter was the presence or absence of a clinically significant fracture. There were 351 patients in the study; 26 (7%) had knee fractures. Fractures were significantly associated with an increased prevalence for two of the three criteria in the rule derived by Bauer: inability to weight bear immediately or in the emergency department (ED; 76.9% of patients with a fracture vs. 29.8% of patients without a fracture) and effusion (53.8% vs. 28.9%, respectively). Ecchymosis was not significantly associated with fracture (19.2% with fracture vs. 9% with no fracture). Use of the Bauer rule would have led to a radiographic evaluation of 22 of the 26 patients with knee fractures (sensitivity = 84.6%, specificity = 48.9%). Fractures were associated with a significantly increased prevalence for three of the five criteria in the decision rule proposed by Stiell: isolated patella tenderness (30.8% with fracture vs. 14.5% with no fracture), inability to flex the knee to 90 degrees (42.3% vs. 19.7%, respectively), and inability to weight bear immediately and in the ED (57.7% vs. 18.8%, respectively). Age > or = 55 yr (23.1% vs. 12.0%, respectively) and fibula head tenderness (11.5% vs. 5.5%, respectively) were not significantly associated with fracture. Use of the Stiell rule would have led to radiographic evaluation of 22 of the 26 patients with knee fractures (sensitivity = 84.6%, specificity = 49.8%). We conclude that neither clinical decision rule is 100% sensitive. Further refinement will be necessary to identify all patients with knee fractures.

Bolus i.v. nitroglycerin treatment of ischemic chest pain in the ED.

A prospective case series was conducted to demonstrate the safety and efficacy of intravenous nitroglycerin (i.v. NTG) boluses in the treatment of ischemic chest pain (CP) in the emergency department (ED). Patients with CP symptomatic after sublingual nitroglycerin (SL NTG) therapy with a systolic blood pressure (SBP) greater than 95 mmHg were included. Patients were treated with i.v. NTG boluses of 0.05 mg to 0.4 mg during a 1- to 2-minute period per a protocol based on the patient's prebolus SBP. This was followed by a maintenance infusion. Additional NTG boluses were repeated every 5 minutes as needed. The end point of treatment was the resolution of chest discomfort, thrombolysis, or a SBP less than 95 mmHg. There were 16 cases of CP. All 16 patients treated, ie, 5 with acute myocardial infarction and 11 with unstable angina showed significant decrease in chest discomfort after 1 to 2 boluses. Two of five with acute myocardial infarction and 9 of 11 patients with unstable angina had complete relief of chest pain after 1 to 4 boluses. There were no episodes of hypotension (SBP < 90 mmHg) in any of the 16 cases. The judicious use of i.v. NTG boluses administered during a 1- to 2-minute period, in the ED, appears safe and efficacious in patients with CP unresponsive to SL NTG therapy.

Effect of cardiac dysfunction upon diastolic cerebral blood flow.

The transcranial Doppler (TCD) studies performed in 54 patients with various forms of cardiac dysfunction were reviewed and the results compared with those of normal individuals. There were 4 patients with aortic insufficiency, 5 being treated by intra-aortic balloon pumps, 12 patients with atrial fibrillation, 11 with syncope, and 22 undergoing cardiopulmonary resuscitation. In all instances, significantly low or even absent diastolic cerebral perfusion was found. The importance of this parameter, in the future evaluation and management of similar patients, is discussed.

Clonal analysis of cytotoxic and regulatory T cell responses against human melanoma.

T cell-mediated immune response against autologous melanoma cells was analyzed, at population and clonal levels, in 31 patients with recurrent and/or metastatic disease. Fresh PBL and lymph node lymphocytes (LNL) from melanoma-involved nodes were not cytotoxic against the respective melanoma cells. When activated in in vitro coculture (IVC) against the autologous melanoma cells in the presence of IL-2, a majority of the activated PBL and LNL became cytotoxic against the autologous targets. The activated effector cells were cloned in limiting dilution microcultures, and growing clones were phenotypically defined and were functionally characterized for cytotoxicity and for potential regulatory function. Functional T cell clones were obtained from 15 of 31 cases. Of these, CTL responses exhibiting cytotoxicity restricted against the autologous melanoma were seen in four cases. All four CTL clones were CD3+, CD8+, and CD4-. Three of these four CTL clones were studied extensively. All three of these CTL clones expressed MHC class I-restricted cytotoxicity. mAb anti-CD3 blocked cytotoxicity in two and enhanced cytotoxicity in the other. Neither autologous sera nor autologous nonactivated fresh PBL modulated the cytotoxic functions of the CTL clones at the effector phase. T cell lines exhibiting regulatory function were obtained in 11 cases. The regulatory T cell lines were CD3+, CD4+, and CD8-. In three cases CD4+ clones amplified the cytotoxic response in the PBL in coculture, while in eight other cases the T cell lines downregulated the cytotoxic responses. Such T cell-mediated down-regulations were either restricted to the autologous system, induced by D/DR antigens expressed by the autologous or allogeneic melanoma cells, or induced by stimulus other than D/DR antigens. Taken together, these findings clearly demonstrate the existence of T cell-mediated cytotoxic and regulatory responses against human melanoma.

Automated differential leukocyte counts.

Automated differential counts have the advantage of precision, efficiency, safety, and economy. They could potentially serve effectively in 90 percent of patients with normal counts or in 75 percent of patients with anemia only (64 percent of the total in this study). Even patients with increased white blood cell counts and major population shifts (toward granulocytes or lymphocytes) could be followed with automated differential counts. Such a tactic would decrease turnaround time for results, be less expensive, and reduce exposure of technologists to direct contact with patients' blood. However, presently available instruments fail to detect patients' blood samples with small numbers of abnormal cells, e.g., blasts in early relapse of acute leukemia, atypical lymphocytes in viral diseases such as infectious mononucleosis, eosinophils in allergic or parasitic disease, and band forms in early infectious diseases. Clinical judgment should be used in selectively ordering manual differential counts for these patients. While automated differential counts can be very useful in screening general medical and surgical patients in the ambulatory setting, in referral centers where hematologic abnormalities are more prevalent, the manual differential count and further examination of a smear is particularly necessary at least on initial presentation. Selective manual differential counts may improve efficiency, economy, and safety while not compromising patient care. Further studies of the correlation of clinical disease with automated differential counts are necessary.

T-cell surface molecules involved in the induction and expression of lymphokine-activated killing of autologous and allogeneic tumor targets.

The cellular interactions and the surface molecules involved in the generation and the expression of lymphokine-activated killer-cell (LAK) activities in vitro in blood mononuclear cells (BMN) from cancer patients and healthy individuals against autologous and allogeneic tumors were studied. The depletion of a plastic-adherent population(s) from BMN at the initiation of in vitro cultures in recombinant interleukin-2 (rIL-2) markedly interfered with the generation of LAK activities. Readdition of the same number of irradiated autologous plastic-adherent cells to the nonadherent population restored the generation of LAK. The requirement of the plastic-adherent population(s) in in vitro induction of LAK activities was observed only in autologous situations. Furthermore, selective modulations of CD3 and CD2 receptors on BMN with the appropriate monoclonal antibodies (MAb) during the induction phases of LAK responses profoundly inhibited the generation of LAK. Thus, unhindered expression of CD2 molecules and CD3 molecules were necessary for the maximum cytotoxic activation of non-antigen-driven effector cells in short-term cultures in rIL-2.