The natural history of cigarette smoking from adolescence to adulthood: demographic predictors of continuity and change

The current study examined the natural history of smoking from adolescence to adulthood in a community sample. Participants were from a longitudinal study (N = 4,035, 51.7% female, average age = 29 years). Group-level analyses showed a significant increase in smoking from adolescence to young adulthood and a nonsignificant decline after the mid-20s. Individual-level analyses showed that there was appreciable cessation and relapse but little new initiation in adulthood. Both adolescent and young adult smoking status were powerful predictors of adult smoking. Moreover, there was less cessation among less educated individuals and those with smoking parents, and more cessation among those who assumed adult social roles. The findings support the importance of prevention campaigns aimed at adolescent smoking and also suggest that those with lower educational attainment or with a family history of smoking are at heightened risk.

Prospective predictors of quit attempts and smoking cessation in young adults

This study examined prospective predictors of attempts to quit smoking and successful quitting among those who attempted to quit (n = 700), using a long-term longitudinal study of the natural history of cigarette smoking in a midwestern community sample. Participants, originally surveyed in 6th-12th grade (1980-1983), were followed up in 1987 and 1994. Results showed that amount of smoking, gender, education, health beliefs about smoking, value on healthy lifestyle, motives for smoking, reasons for quitting, and occupancy of young adult social roles were significant predictors of cessation. However, there were different predictors of attempts to quit and successful quitting among those who attempted to quit. From a public health perspective, both predictors of quit attempts and predictors of successful quitting among attempters are useful targets for intervention.

Cerebral perfusion in early and late opiate withdrawal: a technetium-99m-HMPAO SPECT study

The purpose of this study was to determine if cerebral blood flow (CBF) alterations are associated with discontinuation of heroin in chronic heroin users, and whether these alterations are reversible during abstinence. Ten physically healthy opioid-dependent males, hospitalized on an inpatient drug rehabilitation unit, were studied. Each patient had an initial single photon emission computed tomographic (SPECT) scan with the radiotracer technetium-99m-d,l-hexamethylpropyleneamine oxime (99mTc-HMPAO) 1 week after opiate discontinuation and a repeat scan 2 weeks later. The initial scans in 9 of the 10 subjects demonstrated significant, often discrete, perfusion defects, especially in the frontal, parietal, and temporal cortices. Two weeks later, repeat brain perfusion SPECT scans showed improvement in all nine subjects who had abnormal scans. Comparisons of the first scan with the second scan showed an increase in cortical uptake on the repeat SPECT study. All subjects had normal computed tomographic or magnetic resonance imaging scans. The results of this preliminary study suggest that the chronic use of opiates, like chronic use of cocaine, results in perfusion abnormalities without corresponding abnormalities on imaging studies of cerebral anatomy and morphology. This study also documents that these perfusion defects are partially reversible with short-term abstinence.

Cocaethylene: a current understanding of the active metabolite of cocaine and ethanol

Cocaine and ethanol abuse remains a major problem in our society. The active metabolite of the co-ingestion of cocaine and ethanol, cocaethylene, has been reported recently. This active and potentially toxic metabolite has enormous implications for emergency physicians. This article is a brief review of the current understanding of cocaethylene and its role as a serious toxin in the practice of emergency medicine.

Code blue: what's new?

In October 1992, lengthy new guidelines for cardiopulmonary resuscitation and emergency cardiac care were published by the Emergency Cardiac Care Committee and Subcommittees of the American Heart Association. These guidelines represent the efforts of the world's experts in emergency cardiac care. Yet they may be difficult for the busy clinician to digest in a timely fashion. In this article we summarize the changes in the guidelines from the 1986 version. It is not intended as a substitute for the original document but rather as an adjunct to help the clinician assimilate this new information.

Three-dimensional time-of-flight MR angiography with a specialized gradient head coil

A gradient head coil has been developed, incorporating two independent gradients within the conventional body coil of the magnetic resonance (MR) system, with reduced rise times (200 microseconds) and maximum amplitudes of 37 and 18 mT/m in the z and y directions, respectively. This gradient coil was systematically evaluated by testing two-dimensional (2D) and three-dimensional (3D) time-of-flight (TOF) MR angiography sequences applied to a pulsatile flow phantom simulating a carotid stenosis and the intracranial vasculature. When standard 2D and 3D TOF MR angiography techniques were used to image the carotid stenosis model, dramatic signal loss in the stenotic segment and a large flow void distal to the stenosis were seen. The shorter (3.8 msec) absolute echo times (TEs) achievable with the gradient coil in 3D sequences substantially reduced the phase dispersion and associated signal loss in the region of stenosis. Shorter TEs alone (3.2 msec) did not minimize signal loss, and first-order flow compensation in the read and section-select directions provided further improvements (despite slightly longer TEs). Reduction of TEs in 2D sequences yielded relatively poor results regardless of the refocusing scheme or TE. This study confirms the predicted benefits of a dedicated coil with improved gradient capabilities for 3D MR angiography. The study suggests the limitations of 2D TOF MR angiography in the evaluation of severe stenoses.

Beta 2 microglobulin on the envelope of urinary cytomegalovirus is not associated with host class I human leukocyte antigen alpha chain

Previous studies have shown that beta 2 microglobulin (beta 2m) is associated with glycoproteins present on the envelope of urinary human cytomegalovirus (CMV). beta 2m is non-covalently associated with the alpha chain of human leukocyte antigen (HLA) class I antigens and therefore it was of interest to determine whether the class I alpha chain is also associated with the beta 2m-CMV complex. Using a panel of monoclonal antibodies recognizing different conformational determinants on the HLA class I heterodimer or free beta 2m, we have shown that beta 2m but not the alpha chain of HLA class I could be immunoprecipitated from 125I-surface-labelled virions purified directly from urine. We therefore conclude that host class I HLA alpha chains are not associated with beta 2m on the envelope of urinary CMV.

Exposure therapy for post-traumatic stress disorder. Four case studies

Four cases of PTSD, and their treatment, are described. Symptoms responded differently to two behavioural approaches. In-vivo exposure was effective for phobic anxiety while imaginal exposure improved dysphoria and some phobic symptoms. Audio-taped imaginal exposure may be important as part of treatment.

The role of interleukin 6 and interleukin 1 in megakaryocyte development

The effect of human interleukin 6 (IL-6) and interleukin 1 (IL-1) on cells of the megakaryocyte lineage from murine bone marrow was examined. In bone marrow liquid culture, IL-6 but not IL-1 increases the amount of acetylcholinesterase, a megakaryocyte marker. In semisolid colony assays, a low level of interleukin 3 (IL-3) was used as a growth factor, and IL-6 and IL-1 were tested for their ability to potentiate the activity of IL-3 to stimulate megakaryocyte colony formation. IL-6 and/or IL-1 had no effect on megakaryocyte colony formation in the absence of IL-3. However, IL-6 was able to stimulate increased megakaryocyte colonies in the presence of IL-3. IL-1 was able to potentiate colony formation only in the presence of both IL-3 and IL-6.

Decline in inducibility of sustained ventricular tachycardia from two to twenty weeks after acute myocardial infarction

To determine temporal evolution of sustained ventricular arrhythmias inducible after acute myocardial infarction (AMI), serial programmed ventricular stimulation (PVS) was performed in 27 patients 15 +/- 4 and 150 +/- 28 days after AMI. These patients did not have worsening of congestive heart failure or angina, coronary artery bypass surgery or spontaneous sustained ventricular tachycardia (VT) in the period between 2 PVS studies. During initial PVS, sustained VT or ventricular fibrillation (VF) was inducible in 17 patients (group I) and was not inducible in 10 (group II). Late PVS in group I induced sustained VT or VF in 8 patients (47%) and nonsustained VT or no VT in 9 (53%). A decrease in late inducibility of sustained VT/VF was greater for arrhythmias induced during initial PVS by triple extrastimuli and burst pacing than for those induced by double extrastimuli (88% vs 25%, p less than 0.04), but appeared to be unrelated to the morphologic characteristics or cycle length of the initially induced sustained VT or VF and to other clinical, hemodynamic or angiographic variables. During late PVS in 10 group II patients, sustained VT or VF remained noninducible in 9 (90% concordance); in 1 patient sustained VT was induced. During a mean follow-up of 14 +/- 5 months since late PVS, none of 27 patients had spontaneous sustained VT and 2 patients in group I died suddenly.(ABSTRACT TRUNCATED AT 250 WORDS)

Effective termination of reentrant supraventricular tachycardia by single dose oral combination therapy with pindolol and verapamil

We evaluated the efficacy of single oral dose combining 20 mg pindolol and 120 mg verapamil in termination of paroxysmal supraventricular tachycardia (SVT) in 12 patients with recurrent symptomatic tachycardia. All had electrically inducible SVT lasting longer than 30 minutes. Patients were administered placebo or crushed pindolol and verapamil on 2 consecutive days after tachycardia was electrically induced and allowed to sustain for 30 minutes. With placebo, SVT lasted 186 +/- 18 minutes (mean +/- SEM); five patients converted spontaneously within 121 to 180 minutes. With pindolol and verapamil, 9 of 12 patients (responders) converted to sinus rhythm within 8 to 74 minutes. The mean duration of SVT in the nine responders was 28 +/- 8 minutes compared with 168 +/- 20 minutes on placebo (p less than 0.001). Before termination, tachycardia rate on pindolol and verapamil slowed significantly from 182 +/- 5 to 164 +/- 7/min (p less than 0.05) compared with no significant change in the rate of SVT on placebo. The mean systolic blood pressure during tachycardia was 97 +/- 5 mm Hg with placebo and 101 +/- 7 mm Hg with pindolol and verapamil. Serum levels of pindolol and verapamil obtained in seven patients at time of spontaneous termination of tachycardia were 66 +/- 13 and 56 +/- 14 ng/ml, respectively. The side effects with pindolol and verapamil included lightheadedness in one patient and symptoms of rapid palpitations in three. A single oral dose of pindolol and verapamil is safe and effective in termination of acute paroxysmal SVT and may be the initial therapy of choice in selected patients.

Hypercalcemia in association with mesoblastic nephroma: report of a case and review of the literature

Hypercalcemia, often associated with certain types of adult tumors, has also been described in pediatric neoplasms. In childhood, the more common associations include lymphoma, leukemia, rhabdomyosarcoma and rarely neuroblastoma. However, recently, several infants with hypercalcemia were described having renal tumors without bone metastases. The following is a case report of a 2-month-old infant who presented with severe hypercalcemia and a large right-sided abdominal mass, which at surgery was diagnosed as a cellular mesoblastic nephroma.

Frequency and significance of induced sustained ventricular tachycardia or fibrillation two weeks after acute myocardial infarction

Electrophysiologic study, 24-hour ambulatory electrocardiographic monitoring, treadmill exercise test and angiographic evaluations were performed in 45 patients 14 +/- 3 days (mean +/- standard deviation) after acute myocardial infarction. Electrophysiologic study protocol included burst ventricular pacing and 1 to 3 ventricular extrastimuli at 2 cycle lengths from right ventricular apex, right ventricular outflow and left ventricle. Sustained monomorphic ventricular tachycardia (VT) (13 patients) or ventricular fibrillation (VF) (7 patients) was induced in 20 patients (44%) (group I). In these 20 patients, VT/VF was inducible with 2 extrastimuli in 10 patients, 3 extrastimuli in 9 patients and burst pacing in 1 patient. In the remaining 25 patients (56%), induction of no fewer than 7 ventricular beats were noted (group II). Severe left ventricular (LV) wall motion abnormalities occurred in 70% of group I patients and 22% of group II patients (p less than 0.005). There was no difference in the site of infarction, frequency and grade of ventricular ectopic rhythm on ambulatory electrocardiographic monitoring, double product on submaximal exercise, LV ejection fraction, and number of obstructed coronary arteries (70% or greater) (p greater than 0.1) between group I and group II patients. During a mean follow-up of 10 +/- 3 months, 1 patient in each group died suddenly, and in 1 group I patient spontaneous sustained VT developed which was identical in morphologic configuration to that induced during electrophysiologic study. In conclusion, electrical induction of sustained VT or VF during electrophysiologic study is common in patients 2 weeks after acute myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)

Echocardiographic demonstration of pulmonary embolism as it evolves through the right heart chambers

In three patients with pulmonary embolism, two-dimensional echocardiography demonstrated thrombi within the right heart chambers. These thrombi, suspected of embolizing into the pulmonary circulation, showed varied morphology and mobility. Of the two patients undergoing embolectomy, only one survived. The third patient improved with anticoagulation therapy. Two-dimensional echocardiography is useful in evaluating patients suspected of having pulmonary thromboembolism because it may demonstrate evolution of the thrombus.

Accuracy of determination of changes in cardiac output by transcutaneous continuous-wave Doppler computer

The value of a previously validated portable, continuous-wave Doppler computer was assessed for measuring changes in cardiac output (CO). Simultaneous thermodilution and Doppler CO values were measured in triplicate in 16 patients undergoing clinical intervention with vasodilator therapy. A continuous-wave Doppler transducer was placed in the suprasternal notch and directed toward the ascending aorta and angled until the maximal velocity signal was obtained. The correlation coefficient was 0.92 (standard error of the estimate [SEE] = 0.48 liter/min) at rest; with intervention it was 0.88 (SEE = 0.52 liter/min). Our data indicate that the Doppler computer technique, when used in selected patients, is reliable in detecting changes in CO after vasodilator therapy. It may be of value in clinical situations in which hemodynamic monitoring is impractical.

Tumor infiltration of the bone marrow: comparative study using computed tomography

During the past two years five patients with malignant primary bone tumors undergoing amputation or resection of the involved bone had preoperative computed tomography (CT) examination of the medullary cavity. The contralateral extremity was used as a control in all cases. The positive attenuation coefficient of the marrow indicated the extent of tumor infiltration. The correlation between the preoperative CT and pathologic measurement ranged between 1-8 mm, an accuracy greater than 94%.

Extraskeletal Ewing sarcoma with computed tomography correlation

Extraosseous Ewing sarcoma--a rare clinical entity--is described and the radiographic and histologic features discussed. Histologically this type of tumor may be differentiated from other soft tissue malignancies, but the ultrastructural glycogen content of the cytoplasm makes it frequently inseparable from the conventional osseous form of Ewing sarcoma. In spite of the presence of a huge paraosseal mass with bone erosion or periosteal new bone, computed tomography was the only preoperative modality able to provide evidence of non-involvement of the marrow cavity. However, histologic documentation is necessary to prove that one is dealing with a totally extraosseous Ewing sarcoma.

Bronchogenic cysts with high CT numbers

Four patients with mediastinal masses are described. CT examinations demonstrated masses of high attenuation, and solid masses were suspected. At thoracotomy each patient had a cystic mass containing a brownish, turbid, mucoid material. The pathologic diagnosis in each case was a bronchogenic cyst. The possibility of such a cyst should not be excluded because of a high CT number, which reflects the turbid contents of the cyst.

Unrecognized aspiration of an oropharyngeal airway

A case of unsuspected aspiration of an oropharyngeal airway causing dysphagia is described. Visualization of this airway on plain film would be facilitated if radio-opaque material were included at manufacture.