Interaction of adenosine and naloxone on regional cerebral blood flow in morphine-dependent rats

The present research aimed at investigating the opioid-adenosine interaction on regional cerebral blood flow (rCBF). Therefore rCBF in the sensory cortex of morphine-naive and -dependent rats was measured using the laser-Doppler flowmetry technique. The results showed that adenosine (10(-5), 10(-4), 10(-3) M) significantly increased rCBF in morphine-dependent rats (MDR) (P < 0.01). This effect was inhibited by theophylline (5 x 10(-5) M). Also systemic naloxone (0.5, 1.5 and 3 mg/kg, s.c.) significantly increased rCBF in MDR and it was accompanied by elevated blood pressure and heart rate. Local adenosine (10(-4) M) significantly augmented naloxone (0.5 mg/kg)-induced increase in rCBF of MDR but had no significant effect on naloxone's (1.5 and 3 mg/kg) increasing effect on rCBF. Theophylline also has no effect on naloxone increasing effect on rCBF. These data suggest that adenosine receptors responsiveness increase in sensory cortex of MDR. Naloxone also highly increased rCBF of MDR that probably not interfere with adenosine receptors. Also, it seems that adenosine acts as a modulator in rCBF regulation of morphine-dependent and morphine withdrawal rats.     

Comparison of Salivary and Serum Glucose Levels in Diabetic Patients

Background:Diabetes mellitus is a noncommunicable disease with a rising prevalence worldwide and in developing countries. The most commonly used diagnostic biofluid for detection of glucose levels is blood, but sample collection is an invasive and painful procedure. Thus, there arises a need for a noninvasive and painless technique to detect glucose levels.Results:The findings of present study revealed a significant correlation between salivary and serum glucose levels in both diabetic and nondiabetic subjects. No significant relationship was observed between salivary glucose levels and gender or age in both diabetics and nondiabetics and between salivary glucose levels and duration of diabetes in diabetics.Conclusion:On the basis of the findings, it was concluded that salivary glucose levels could serve as a potentially noninvasive adjunct to monitor glycemic control in diabetic patients.     

Acute and chronic hemodynamic effects of xamoterol in mild to moderate congestive heart failure.

Xamoterol, a new beta 1 partial agonist, has the potential to modulate cardiac response to variations in sympathetic tone in patients with heart failure. Its properties should result in beta-receptor stimulatory effects at low levels of sympathetic tone and beta-receptor protective effects at higher levels of sympathetic tone. The acute effects of intravenous (i.v.) xamoterol on hemodynamics at rest and during exercise were studied in 30 patients with mild to moderate heart failure (13 patients in New York Heart Association class II; 17 in class III) due to ischemic (n = 24) or cardiomyopathic (n = 6) heart disease. Cardiac index, stroke volume and stroke work index at rest were significantly improved after i.v. administration of xamoterol and consistent with net agonist effects. During exercise, heart rate and double product were significantly reduced (net antagonist effects), but with preservation of the expected increases in cardiac index and systolic blood pressure. These hemodynamic findings confirm the ability of xamoterol to modulate cardiac response to variations in sympathetic tone. Tachyphylaxis and arrhythmogenicity limit the chronic use of drugs with full beta-agonist properties as positive inotropes in heart failure. The patients were therefore entered into a 6-month double-blind, placebo-controlled, crossover study of chronic oral xamoterol therapy, 200 mg twice daily, and the hemodynamic responses to i.v. xamoterol were repeated at the end of the trial. No impairment in either resting or exercise effects was observed, indicative of a maintained response and absence of tachyphylaxis after chronic therapy. Furthermore, 24-hour ambulatory electrocardiographic monitoring showed no change in ventricular arrhythmias during oral treatment.(ABSTRACT TRUNCATED AT 250 WORDS)     

Detection of Individual Prostate Cancer Foci via Multiparametric Magnetic Resonance Imaging

Background

Multiparametric magnetic resonance imaging (mpMRI) undoubtedly affects the diagnosis and treatment of localized prostate cancer (CaP). However, clinicians need a better understanding of its accuracy and limitations in detecting individual CaP foci to optimize management.

Agonist-specific regulation of mu-opioid receptor desensitization and recovery from desensitization

Agonist-selective actions of opioids on the desensitization of mu-opioid receptors (MORs) have been well characterized, but few if any studies have examined agonist-dependent recovery from desensitization. The outward potassium current induced by several opioids was studied using whole-cell voltage-clamp recordings in locus ceruleus neurons. A brief application of the irreversible opioid antagonist beta-chlornaltrexamine (beta-CNA) was applied immediately after treatment of slices with saturating concentrations of opioid agonists. This approach permitted the measurement of desensitization and recovery from desensitization using multiple opioid agonists, including [Met](5)enkephalin (ME), [d-Ala(2),N-Me-Phe(4),Gly(5)-ol]-enkephalin (DAMGO), etorphine, fentanyl, methadone, morphine, morphine-6-glucuronide, oxycodone, and oxymorphone. The results indicate that desensitization protects receptors from irreversible antagonism with beta-CNA. The amount of desensitization was measured as the decrease in current during a 10-min application of a saturating agonist concentration and was a good predictor of the extent of receptor protection from irreversible inactivation with beta-CNA. After desensitization with ME or DAMGO and treatment with beta-CNA, there was an initial profound inhibition of MOR-induced current that recovered significantly after 45 min. There was, however, no recovery of MOR-mediated current with time after treatment with agonists that did not cause desensitization, such as oxycodone. These results demonstrate that desensitization prevents irreversible inactivation of receptors by beta-CNA.     

Three Cases of Comprehensive Dietary Therapy and Pharmacotherapy of Patients with Complex Obesity-related Diseases

The effect of weight loss with anorectic medications on sleep apnea, non-insulin-dependent diabetes, and steatohepatitis is illustrated in three cases from practice in a clinical nutrition setting. Prevention of obesity, a chronic disorder, is preferable, but when obesity becomes a major obstacle in the care of patients with respiratory, cardiovascular, and metabolic disorders and osteoarthritis, an intense course of weight reduction using anorectic medications under medical and dietetic guidance is essential for patients' survival and reduction of medical cost.