Interaction between the amino and carbonyl groups in copoly(2-dimethylaminoethyl methacrylate/N-phenylmaleimide)

Interactions between the carbonyl and amino groups in copolymers of 2-dimethylaminoethyl methacrylate with N-phenylmaleimide are reported. The existence of interactions ensues from potentiometric measurements and UV-VIS spectra. Interactions in these copolymers result in the formation of energetically very advantageous chromophores, reflected in an intense red colour of the substances obtained.     

A social-psychological perspective on successful community control of high blood pressure: A review

This review brings together studies dealing with factors that affect participation in screening, referral, and treatment for high blood pressure (HBP). Community-based screening programs are examined first, in order to describe the changing and the current distribution of hypertensives as unaware, untreated, treated but uncontrolled, and controlled by treatment. Factors influencing this distribution are examined. Next, data on referral, acceptance of treatment, and staying in treatment are discussed, with a special reference to intervention studies. The review then brings in the broader social science literature on the psychosocial dynamics of health-maintaining and risk-reducing behaviors. The article concludes with an interpretive summary and some suggestions for further action.     

Differential Effects of Cocaine on Dopamine Neuron Firing in Awake and Anesthetized Rats

Cocaine (benzoylmethylecgonine), a natural alkaloid, is a powerful psychostimulant and a highly addictive drug. Unfortunately, the relationships between its behavioral and electrophysiological effects are not clear. We investigated the effects of cocaine on the firing of midbrain dopaminergic (DA) neurons, both in anesthetized and awake rats, using pre-implanted multielectrode arrays and a recently developed telemetric recording system. In anesthetized animals, cocaine (10 mg/kg, intraperitoneally) produced a general decrease of the firing rate and bursting of DA neurons, sometimes preceded by a transient increase in both parameters, as previously reported by others. In awake rats, however, injection of cocaine led to a very different pattern of changes in firing. A decrease in firing rate and bursting was observed in only 14% of DA neurons. Most of the other DA neurons underwent increases in firing rate and bursting: these changes were correlated with locomotor activity in 52% of the neurons, but were uncorrelated in 29% of them. Drug concentration measurements indicated that the observed differences between the two conditions did not have a pharmacokinetic origin. Taken together, our results demonstrate that cocaine injection differentially affects the electrical activity of DA neurons in awake and anesthetized states. The observed increases in neuronal activity may in part reflect the cocaine-induced synaptic potentiation found ex vivo in these neurons. Our observations also show that electrophysiological recordings in awake animals can uncover drug effects, which are masked by general anesthesia.     

Electrophysiologically identified subpopulations of taste bud cells

The heterogeneous population of mammalian taste cells includes several cellular subtypes specializing in distinct physiological functions. They are poorly understood at the single cell level because the available physiological data have generally been obtained from unidentified taste cells. We recorded them from individual taste cells isolated from circumvallate, foliate, and fungiform papilla of the mouse, employing the patch clamp technique, and tried to elucidate whether universal electrophysiological criteria may be established for the identification of functionally different cellular subpopulations. It was found that irrespective of the papillae type, most ( approximately 96%) of robust taste cells could be categorized into three distinct subgroups on the basis of families of whole-cell (WC) currents exhibited in response to membrane polarization. The validity of this quite simple criterion was further confirmed by using different voltage clamp protocols, ion substitutions, and channel blockers to record different ionic currents, including voltage-gated (VG) Ca(2+), inward-rectifying K(+), and hyperpolarization-activated currents. Given that our findings are based on the statistically significant number of recordings, we believe that the electrophysiological identification of taste cells presented here may be effective for further studies on single taste cell physiology, including taste transduction.     

Intraluminal high dose rate brachytherapy of tumorous esophageal stenoses

BACKGROUND/AIMS: The prognosis of inoperable carcinomas of esophagus is poor, and therapeutic efforts are generally limited to palliation. The aim of this study was to retrospectively evaluate the effectiveness of intraluminal high dose rate brachytherapy in the palliative treatment of tumorous esophageal stenoses. METHODOLOGY: Between February 1997 and July 2002 intraluminal brachytherapy was performed in 19 patients with inoperable esophageal carcinoma (squamous cell carcinoma in 14 cases and adenocarcinoma in 5 cases). All patients had dysphagia at presentation. Brachytherapy was performed using high dose rate afterloading system. RESULTS: Dysphagia was improved in all patients. The mean survival was 248 days. No mechanical complications were observed during introduction of the applicator. CONCLUSIONS: Our experience indicates that intraluminal brachytherapy is an effective and safe method of palliation of dysphagia caused by malignant esophageal stenosis.     

The persistence of depressive symptoms in older workers who experience involuntary job loss: results from the health and retirement survey

OBJECTIVES: The purpose of this study was to investigate the association between involuntary job loss among workers nearing retirement and long-term changes in depressive symptoms. METHODS: Analyzing data from the first four waves (1992-1998) of the Health and Retirement Survey, we used longitudinal multiple regression in order to assess whether involuntary job loss between Wave 1 and Wave 2 was associated with depressive symptoms at Wave 3 and Wave 4. The study sample included 231 workers who had experienced job loss in the Wave 1-Wave 2 interval and a comparison group of 3,324 nondisplaced individuals. We analyzed the effect of job loss on depressive symptoms both in the full study sample and in subsamples determined by wealth. RESULTS: Among individuals with below median net worth, Wave 1-Wave 2 involuntary job loss was associated with increased depressive symptoms at Wave 3 and Wave 4. We found no effect of involuntary job loss for high net worth individuals at the later survey waves. DISCUSSION: Our findings identify older workers with limited wealth as an important group for which the potential effect of involuntary job separation in the years preceding retirement is ongoing (enduring) adverse mental health.     

A Randomized Trial of a Physical Conditioning Program to Enhance the Driving Performance of Older Persons

Background As the number of older drivers increases, concern has been raised about the potential safety implications. Flexibility, coordination, and speed of movement have been associated with older drivers’ on road performance. Objective To determine whether a multicomponent physical conditioning program targeted to axial and extremity flexibility, coordination, and speed of movement could improve driving performance among older drivers. Design Randomized controlled trial with blinded assignment and end point assessment. Participants randomized to intervention underwent graduated exercises; controls received home, environment safety modules. Participants Drivers, 178, age ≥ 70 years with physical, but without substantial visual (acuity 20/40 or better) or cognitive (Mini Mental State Examination score ≥24) impairments were recruited from clinics and community sources. Measurements On-road driving performance assessed by experienced evaluators in dual-brake equipped vehicle in urban, residential, and highway traffic. Performance rated three ways: (1) 36-item scale evaluating driving maneuvers and traffic situations; (2) evaluator’s overall rating; and (3) critical errors committed. Driving performance reassessed at 3 months by evaluator blinded to treatment group. Results Least squares mean change in road test scores at 3 months compared to baseline was 2.43 points higher in intervention than control participants (P = .03). Intervention drivers committed 37% fewer critical errors (P = .08); there were no significant differences in evaluator’s overall ratings (P = .29). No injuries were reported, and complaints of pain were rare. Conclusions This safe, well-tolerated intervention maintained driving performance, while controls declined during the study period. Having interventions that can maintain or enhance driving performance may allow clinician–patient discussions about driving to adopt a more positive tone, rather than focusing on driving limitation or cessation.