Emission Characteristics and Effect of Battery Drain in "Budget" Curing Lights.

Recently, "budget" dental light-emitting diode (LED)-based light-curing units (LCUs) have become available over the Internet. These LCUs claim equal features and performance compared to LCUs from major manufacturers, but at a lower cost. This study examined radiant power, spectral emission, beam irradiance profiles, effective emission ratios, and the ability of LCUs to provide sustained output values during the lifetime of a single, fully charged battery. Three examples of each budget LCU were purchased over the Internet (KY-L029A and KY-L036A, Foshan Keyuan Medical Equipment Co, and the Woodpecker LED.B, Guilin Woodpecker Medical Instrument Co). Major dental manufacturers provided three models: Elipar S10 and Paradigm (3M ESPE) and the Bluephase G2 (Ivoclar Vivadent). Radiant power emissions were measured using a laboratory-grade thermopile system, and the spectral emission was captured using a spectroradiometer system. Irradiance profiles at the tip end were measured using a modified laser beam profiler, and the proportion of optical tip area that delivered in excess of 400 mW/cm(2) (termed the effective emission ratio) was displayed using calibrated beam profile images. Emitted power was monitored over sequential exposures from each LCU starting at a fully charged battery state. The results indicated that there was less than a 100-mW/cm(2) difference between manufacturer-stated average tip end irradiance and the measured output. All the budget lights had smaller optical tip areas, and two demonstrated lower effective emission ratios than did the units from the major manufacturers. The budget lights showed discontinuous values of irradiance over their tip ends. One unit delivered extremely high output levels near the center of the light tip. Two of the budget lights were unable to maintain sustained and stable light output as the battery charge decreased with use, whereas those lights from the major manufacturers all provided a sustained light output for at least 100 exposures as well as visual and audible indications that the units required recharging.

Facial electromyography in depression. Subgroup differences.

To study whether facial electromyographic (EMG) activity during affective imagery differed between normal subjects and depressive subtypes, we evaluated EMG responses in 29 normal controls, 37 endogenously depressed patients, and 26 nonendogenously depressed patients. Different imagery states produced more distinctive EMG patterns in normal controls than in depressed patients. Patients with endogenous depression had EMG levels that differentiated them from normal subjects and had significantly greater absolute values than the nonendogenous group in corrugator happy and corrugator sad imagery trials. Intensity of sad and happy imagery, age, and severity of depression did not systematically correlate with EMG activity among depressive subtypes.

Agitation-increased electromyogram activity in the corrugator muscle region: a possible explanation of the "Omega sign"?

The corrugator muscle region of the forehead has special significance in producing facial expressions associated with depression. Darwin observed in 1872 that contractions in the corrugator region produce peculiarly formed wrinkles on the forehead, referred to as "Omega Melancholium." In the present study, results from 61 right-handed, drug-free women with major depressive disorder showed a significant positive correlation between facial corrugator EMG values and psychomotor agitation. Results were not due to differences in severity of depression. These data offer preliminary evidence that agitation is reflected in corrugator muscle activity and may explain the "Omega sign" of melancholia.

Influence of polyamine architecture on the transport and topoisomerase II inhibitory properties of polyamine DNA-intercalator conjugates.

An efficient five-step synthetic method was developed to access a series of spermine derivatives containing appended acridine, anthracene, and 7-chloroquinoline motifs. The derivatives were composed of a spermine fragment covalently tethered at its N4 and N9 positions to an aromatic nucleus via an aliphatic chain (e.g., 8: acridine -[C4 aliphatic tether]-spermine-[C4 aliphatic tether]-acridine). The distance separating the spermine and aromatic nuclei was altered via different tethers composed of four or five methylene units. These bis ligands (8, 9, 12, and 13) were shown to inhibit human DNA topoisomerase II (topo II) activity at 5 microM. Enzymatic activity was assessed as the ability to unknot (decatenate) and cleave kinetoplast DNA (kDNA). Polyamine conjugation did not disrupt the ability of the acridine-spermine conjugates 8 and 9 to inhibit topo II activity as compared with the 9-aminoacridine and 9-(N-butyl)aminoacridine controls (at 5 microM). The parent polyamines, spermine (5 microM) and spermidine (10 microM), had little effect on topo II activity. In general, the bis-substituted spermine derivatives (8, 9, 12, and 13) were more efficient topo II inhibitors at 5 microM than their monosubstituted spermidine counterparts (22-25) at 10 microM. Within the bisintercalator spermine series, insertion of an additional methylene unit (i.e., C5 tethers) increased potency 2-fold (8, bis-C4-acridine, 47 h IC(50) = 40 microM; 9, bis-C5-acridine, IC(50) = 17 microM). Comparison of the bis- and monoacridine spermine motifs (8 and 17) revealed a 4-fold increase in potency for the latter architecture (94 h IC(50) for 8, 74 microM; for 17, 17 microM). In general the bisintercalators (8, 9, 12, and 13) behaved as cytostatic agents, while the monosubstituted acridine and anthracene derivatives (22-25) were cytotoxic. Anthracene-containing conjugates were generally more toxic than their acridine counterparts in an L1210 (murine leukemia) cell assay. Of the conjugates tested the (monointercalator)-spermine motif (e.g., 17) had the highest affinity for the L1210 polyamine transporter as revealed by spermidine protection experiments.

The signal-averaged electrocardiogram in cardiac transplantation. A noninvasive marker of acute allograft rejection.

Cardiac allograft rejection represents a major cause of morbidity and mortality in transplanted patients. Noninvasive markers of rejection have been sought, though transvenous endomyocardial biopsy remains the "gold standard" for the diagnosis of rejection. Sixty-one signal-averaged electrocardiograms (five in patients with rejection and 56 in patients without rejection) were obtained on 41 patients and prospectively analyzed in frequency domain via fast Fourier transform (FFT). Patients with acute allograft rejection demonstrate a significant increase in the high-frequency components of the QRS complex upon FFT analysis (QRS area ratio 203 +/- 57 vs. 66 +/- 10, P = 0.0007) compared with patients without rejection. Thus, frequency domain analysis may be a useful noninvasive marker of acute cardiac allograft rejection.

Noninvasive and angiographic evaluation of coronary artery disease in patients with peripheral vascular disease.

The accuracy of exercise testing for detection of coronary artery disease in a population with a high incidence of claudication was evaluated in 58 consecutive patients with abdominal aortic aneurysms or lower extremity occlusive disease. Each patient was evaluated by history and physical examination, symptom-limited testing with exercise treadmill, arm ergometry and exercise radionuclide ventriculography. An algorithm was designed that retrospectively examined the results of each test in a stepwise fashion to simulate a clinical decision-making process. The results of the clinical examination, each of the exercise tests and the noninvasive diagnostic algorithm were compared with the results of coronary arteriography. The predictive accuracy of the clinical evaluation was 36%, treadmill stress testing 57%, treadmill stress plus arm ergometry 74%, exercise radionuclide ventriculography 57% and the noninvasive diagnostic algorithm 89%. When discriminant analysis was applied to all of the exercise variables, no individual test improved the accuracy of the noninvasive diagnostic algorithm. When the analysis considered only individual variables without the algorithm, the model correctly classified only 67% of the patients. Thus, accurate noninvasive evaluation of coronary artery disease is possible in patients with severe peripheral vascular disease when care is taken to design exercise protocols that allow adequate stress on the cardiovascular system.

False-positive echocardiographic diagnosis of pericardial effusion. Result of tumor encasement of the heart simulating constrictive pericarditis.

A 46-year-old man had advanced squamous cell carcinoma of the lung and apparent constrictive pericarditis. Echocardiographic studies twice demonstrated apparent pericardial effusions, but pericardiocenteses were unsuccessful. Tumor encasement of the heart was diagnosed clinically and at necropsy. This entity is yet another cause of a false-positive echocardiographic diagnosis of pericardial effusion.

Evaluation of pediatric intensive care scoring systems.

There is no report analysing pediatric severity scoring systems in British Intensive Therapy Units (ICUs). Two previously reported pediatric severity scoring systems, the Admission Physiologic Stability Index (APSI) and the Organ System Failure (OSF) score were evaluated for 151 patients. The APSI was higher for children who died than for those who lived (p less than 0.001). This difference reflected the sharp distinction between the APSI for children who left intensive care within 24 h and those remaining in ICU longer than 24 h (p less than 0.001). For children remaining in ICU longer than 24 h, there was a large overlap of APSI scores, and the APSI did not discriminate between children in the overlap region who lived and those who died (p = 0.054). There was underscoring of neurological patients; the APSI did not differentiate neurological patients whole lived and those who died (p greater than 0.10). The OSF also underscored neurological patients. Increasing number of organ systems failed was associated with increasing mortality. In contrast to previous reports, however, the mortality rate was unaffected by whether the total number of systems failed simultaneously or non-simultaneously. There is still a need for a comprehensive yet simple pediatric scoring system for comparing the efficacy and outcome of pediatric intensive care in different ICUs in different countries.

Current issues in advanced heart failure.

In the past 50 years, an increased understanding of the pathophysiologic mechanisms associated with the development of heart failure has produced a more precise treatment of this syndrome. The effects of the agents used for the treatment of patients with advanced heart failure have been summarized in this article and demonstrate the importance of vasodilatory drugs on the survival and progression of dilated cardiomyopathy.

Lateral asymmetries in arm, wrist and finger movements.

On the assumption of contralateral control, lateral asymmetries in motor performance are often associated with the functional specialization of the cerebral hemispheres. However, anatomical as well as previous behavioral studies, indicate this assumption may not be valid for all joints of the limbs. To test this assumption, right-handed male subjects performed a rapid tapping task using movements of the index finger, the wrist, or the shoulder. The hand used and order of conditions were counterbalanced across subjects. The rate and variability data were submitted to a 2 x 3 (hand x joint) Analysis of Variance with repeated measures on both factors. For both rate and variability significant (all p less than .01) main effects were evident for hand and joint with no significant interactions. It is argued that the variability of tapping reflects the processing mode of the contralateral hemisphere and thus leads to the conclusion that crossed pathways are the principal mechanism for controlling rapid movements of all limb joints. It is tentatively concluded that where either crossed or ipsilateral pathways are available, the type of movement control required will dictate which pathway is used.

Facial EMG activity levels predict treatment outcome in depression.

Higher electromyographic (EMG) activity levels of corrugator and zygomatic face muscles have been reported to be pretreatment predictors of better clinical outcome in depressed patients. We tested this possibility in 29 drug-free, rigorously diagnosed subjects by measuring low-level EMG activity of corrugator and zygomatic muscles during resting and three imagery states (happy, typical day, sad). All patients had major depressive disorder, endogenous subtype. Good responders had significantly higher pretreatment EMG zygomatic values and different EMG profiles. Our findings replicate and expand prior reports.

Induction immunosuppression with the monoclonal antibody OKT3 after cardiac transplantation.

The routine use of monoclonal induction immunosuppression with OKT3 after orthotopic heart transplantation remains controversial. This study examined the clinical response of prophylactic monoclonal induction immunosuppression versus standard triple-drug immunosuppression in 41 patients who underwent orthotopic heart transplantation from January 1989 to December 1990 at this institution. Of these, eight received monoclonal induction immunosuppression for a period of 10 to 14 days. All patients received identical triple-drug immunosuppression with the exception of cyclosporine starting on the fifth postoperative day in those who received OKT3. At 6 months the duration of hospitalization, freedom from rejection, incidence of infection requiring hospitalization, and serum creatinine in the monoclonal induction immunosuppression and triple-drug groups were compared. It was found that the length of hospital stay in the OKT3 group was 14.3 +/- 4.5 days, compared with 14.7 +/- 4.7 days in the triple-drug group and that freedom from rejection was 66% in the OKT3 group compared with 75% in the triple-drug group. In addition, it was found that the incidence of infection was 36% in the OKT3 group compared with 38% in the triple-drug group and that serum creatinine at 6 months was 1.36 +/- 0.26 mg/dl in the OKT3 group compared with 1.45 +/- 0.73 mg/dl in the triple-drug group. Finally, patient survival at 1 year for the monoclonal induction immunosuppression group was 100% compared with 91% for the triple-drug group.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiopulmonary resuscitation. A survey of instruction in physical therapy schools.

Sixty-two physical therapy schools were surveyed reageding their teaching of cardiopulmonary resuscitation. Eighty-two percent of the schools responded to the questions and 27 percent indicated no such instruction. Included in this report is a copy of the questionnaire and the results of the survey. The recommendation is made that all physical therapists receive adequate training in cardiopulmonary resuscitation and that their competency be confirmed by examination.

A computational model of membrane lipid electronic properties in relation to neural signaling.

We present a computational model of a transiently-organized neural membrane molecular system with possible information-processing capacity. The model examines field-induced dipole and quadrupole moments and polarizability in monomeric, dimeric, and trimeric ethenes. Polarization of the ethenes is strongly indicated. This result is interpreted as a significant electronic feature of a molecular computing system based on organization of membrane lipids into a transient ( approximately 10(-4) s) crystalline state due to lipid-protein hydrophobic mismatch at the membrane-ion-channel interface. Predictive implications of the model's electronic features are briefly discussed.

Cardiac transplantation. How recipients are selected.

Your patients with heart disease may ask about transplantation. Those who are potential candidates need a physician who knows enough about the selection system to get them into it. For other patients, an explanation of why the procedure is contraindicated in their case can help them refocus on compliance with recommended therapy. The authors discuss the principles of recipient selection.

Cardiac allograft vasculopathy: current concepts.

The major cause of late death in cardiac transplant recipients is cardiac allograft vasculopathy also referred to as cardiac transplant atherosclerosis which occurs in 15% to 20% of transplant recipients. It differs from traditional atherosclerosis in that it is a concentric and diffuse intimal hyperplastic process, the internal elastic lamina remains intact, and calcification is rare. The distal portion of the coronary vessel is the earliest to occlude, with occlusion occurring rapidly. Sometimes a low grade vasculitis is also present. There is no definitive reason for cardiac allograft vasculopathy occurring though it has been suggested that it may actually be caused by immunologic and nonimmunologic damage to endothelial cells resulting in myointimal proliferation. Intravascular ultrasound and coronary angioscopy seem to be a more sensitive diagnostic measure of cardiac allograft vasculopathy than coronary angiography. To date, retransplantation seems to be the only definitive therapy for cardiac allograft vasculopathy. But only fair results are being seen with this procedure.

Cardiac transplantation: an overview of recipient selection.

Cardiac transplantation is an accepted treatment for end-stage heart disease. Potential recipients are carefully screened in order to best place the short supply of donor organs with the best recipient. The success of heart transplantation in the United States today is directly related to careful donor and recipient selection criteria and improvements in immunosuppression.

Current status of adult spinal deformity.

Purpose To review the current literature for the nonoperative and operative treatment for adult spinal deformity. Recent Findings With more than 11 million baby boomers joining the population of over 60 years of age in the United States, the incidence of lumbar deformity is greatly increasing. Recent literature suggests that a lack of evidence exists to support the effectiveness of nonoperative treatment for adult scoliosis. In regards to operative treatment, current literature reports a varying range of improved clinical outcomes, curve correction, and complication rates. The extension of fusion to S1 compared with L5 and lower thoracic levels compared with L1 remains a highly controversial topic among literature. Summary Most adult deformity patients never seek nonoperative or operative treatment. Of the few that seek treatment, many can benefit from nonoperative treatment. However, in selected patients who have failed nonoperative treatment and who are candidates for surgical intervention, the literature reflects positive outcomes related to surgical intervention as compared with nonoperative treatment despite varying associated ranges in morbidity and mortality rates. If nonoperative therapy fails in addressing a patient's complaints, then an appropriate surgical procedure that relieves neural compression, corrects excessive sagittal or coronal imbalance, and results in a solidly fused, pain-free spine is warranted.