Time-dependent changes in heart rate and pupil size during desflurane or sevoflurane anesthesia

To better characterize alterations in autonomic function associated with prolonged anesthesia, we tested the hypothesis that the time-dependent effects of sevoflurane and desflurane differ. We studied seven male volunteers, each anesthetized for 8 h with 1.25 minimum alveolar anesthetic concentration desflurane on one study day and with 8 h sevoflurane on another. These volunteers did not undergo surgery and were minimally stimulated during the study. Measurements included blood pressure, heart rate, pupillary size and light reactivity, concentrations of serum catecholamines, and carbon dioxide production. Over time, heart rate and pupil size increased significantly. During 6 of the 14 anesthetics (45%), heart rate at some point exceeded 95 bpm; similarly, pupil size at some time exceeded 5 mm during 8 anesthetics (57%). In contrast, plasma catecholamine concentrations and carbon dioxide production remained unchanged, and blood pressure remained nearly constant. There are thus substantial time-dependent changes in autonomic functions during prolonged anesthesia, even in unstimulated, nonsurgical volunteers, but we could not detect a difference in these changes during desflurane compared with sevoflurane anesthesia. Implications: Pupil size and heart rate changes are used to guide the delivery of anesthesia. In volunteers, pupil size and heart rate increased with increasing duration of constant desflurane or sevoflurane anesthesia. Thus, anesthetic duration alters heart rate and pupil size independent of surgery and changes in anesthetic delivery.     

Antibacterial activity of calcium hydroxide-containing endodontic sealers on Enterococcus faecalis in vitro

Nickel-titanium instruments purportedly resist deformation and loss of sharpness better than do stainless steel instruments but may be more susceptible to breakage. The processes of wear and breakage of nickel-titanium and stainless steel instruments were examined. Sixty files of five types (12 each) and three manufacturers were used. All were used repeatedly in curved canals until failure or for a maximum of 22 minutes. Each instrument was examined with scanning electron microscopy both new (control) and at spaced intervals for evidence of wear and fatigue. All new instruments were of good quality. Stainless steel instrument tended to wear the most rapidly, and next were nickel-titanium rotary instruments; the most resistant to wear were nickel-titanium hand instruments. There were few instrument separations. In general, nickel-titanium (particularly hand) instruments resisted deterioration better than did stainless steel. Nickel-titanium rotary instruments (2 of 12) had the most breakage.     

Long-term therapy of bronchial asthma with ingacort

To study the effectiveness of ACE-inhibitors in diabetic nephropathy (DN) 12 male and 16 female patients aged 13-21 years with DN having normal blood pressure (BP) were given ramipril (tritace) in a dose 2.5-5 mg/day in the course of 12-24 weeks. Efficacy and safety of the treatment were assessed by changes in albuminuria and proteinuria, BP. Reduction of albuminuria occurred in 19(79.1%) out of 24 patients with microalbuminuria, in 13(54.1%) of them urine excretion of albumin returned to normal levels. All the patients with proteinuria and macroalbuminuria benefited from ramipril therapy because their proteinuria diminished or even disappeared (2 cases). The persistence of the antiproteinuria effect on posttreatment week 12 was 66.6%. Ramipril effect on BP was minimal. It is inferred that ramipril is effective in the treatment of DN at the stage of microalbuminuria and proteinuria in patients with normal BP.     

Genome sequences of poa semilatent and lychnis ringspot hordeiviruses

The nucleotide sequences of the genomic RNAs of two hordeiviruses, poa semilatent virus (PSLV) and lychnis ringspot virus (LRSV), were determined. The genome organization of both viruses is similar to that of the type hordeivirus, barley stripe mosaic virus (BSMV). Comparisons of the amino acid sequences of the hordeivirus replicase components revealed a high level of sequence similarity to those of soil-borne wheat mosaic virus (SBWMV), peanut clump virus (PCV), and Indian peanut clump virus. The cysteine-rich gamma b proteins of hordeiviruses are similar to those of SBWMV, PCV, and tobraviruses. Analysis of cis-acting elements in the genomes of the three hordeiviruses revealed conservation of putative core elements of subgenomic RNA promoters. Complex patterns of conservation were also found in the 5'-untranslated regions of hordeivirus genomic RNAs alpha, beta, and gamma.     

Activation or frustration of anti-tumor responses by T-cell-based immune modulation

Cataleptogenic effects of haloperidol (1 mg/kg i.p.) in rats was antagonized by caffeine and theophylline (10-50 mg/kg i.p.), and by selective adenosine A2 receptor antagonist (3,7-dimethyl-1-propargylxanthine) (3 and 6 mg/kg i.p.). Selective A1-adenosine receptor antagonist (8-cyclopentyltheophylline) (1.5 and 3 mg/kg i.p.) was not able to reduce this effect of haloperidol. These results confirm the antagonistic interaction between adenosine A2A and dopamine D2 receptors, and suggest the involvement of adenosine A2 receptors in the mechanisms of catalepsy.     

Intravascular ultrasound elastography

Asthma, a chronic disease of the respiratory tract, affects approximately five percent of the U.S. population, including almost five million children. Childhood asthma has been identified as the leading cause of school absences. This study was to examined efficacy of a school-based program to prevent exacerbation of asthma symptoms and manage asthma in school children using measured doses of an inhaled anti-inflammatory medication. The sample consisted of 22 African-American children in one inner-city elementary school in Dallas, Texas, ages 5-12 years with confirmed diagnoses of asthma. For three months, each child came to the school clinic two times per day for medication administration and measurement of respiratory peak flow rates. Data were collected for a number of variables including bronchodilator use, school absences, self-report of asthma symptoms, and number of visits to the physician. During the study, mean peak flow rates improved approximately 15%, and bronchodilator use decreased 66%. Improvement also was evident in several other areas.     

The sequelae of the intraspecific isolation of adult rats (right-handed, left-handed and ambidextrous animals)

We studied the influence of social isolation at the age of 2 months on zoosocial behaviour of mixed-bred male rats with different paw preference. Paw preference was determined in the test of reaching for food in the horizontal tube. The level of aggression but not sociability was found to increase significantly in dextral and ambidextrous late isolants. In sinistrals the increase of sociability but not aggression was observed. Analysis of probabilistic ethological structure of aggressive behaviour showed its validity and revealed the appearance of pathological aggression as a result of isolation in all groups of animals. Being connected with a disfunction of the regulating role of the right brain hemisphere this feature of aggressive behaviour is most pronounced in dextrals and ambidextrals.     

On the recording of sample times and parameter estimation from repeated measures pharmacokinetic data

A pharmacokinetic screen has been advocated for the characterization of the population pharmacokinetics of drugs during Phase 3 clinical trials. A common perception encountered in the collection of such data is that the accuracy of sampling times relative to dose is inadequate. A prospective simulation study was carried out to evaluate the effect of error in the recording of sampling times on the accuracy and precision of population parameter estimates from repeated measures pharmacokinetic data. A two-compartment model with intravenous bolus input(s) (single and multiple doses) was assumed. Random and systematic error in sampling times ranging from 5-50% using profile (block) randomized design were introduced. Sampling times were simulated in EXCEL while concentration data simulation and analysis were done in NONMEM. The effect of error in sampling times was studied at levels of variability ranging from 15-45% for a drug assumed to be dosed at its elimination half-life. One hundred replicate data sets of 100 subjects each were simulated for each case. Although estimates of clearance (CL) and variability in clearance were robust for most of the sampling time errors, there was an increase in bias and imprecision in overall parameter estimation as intersubject variability was increased. If there is interest in parameters other than CL, then the design of prospective population studies should include procedures for minimizing the error in the recording of sample times relative to dosing history.