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PubMed2004

The acute effect of music on interictal epileptiform discharges.

This study was a prospective, randomized, single-blinded, crossover, placebo-controlled, pilot clinical trial investigating the effect of Mozart's Sonata for Two Pianos (K448) on the frequency of interictal epileptiform discharges (IEDs) from the EEGs of children with benign childhood epilepsy with centrotemporal spikes, or "rolandic" epilepsy. The goal was to demonstrate decreased frequency of IEDs with exposure to K448. Four subjects were recruited and 4-hour awake EEG recordings performed. IED frequency per minute was averaged over each of three epochs per hour. Mean IED count per epoch, standard deviations, and variance were calculated. Only complete waking epochs were analyzed. Two subjects demonstrated sufficient waking IEDs for statistical analysis, consisting of three epochs of K448-related effects. Significant decreases in IEDs per minute (33.7, 50.6, and 33.9%) were demonstrated comparing baseline with exposure to K448, but not to control music (Beethoven's Für Elise).

Child↗
PubMed1982

Trial of an ACTH4-9 Analogue (ORG 2766) in children with intractable seizures.

The ACTH4-9 Analogue (ORG 2766) is an orally administered neuropeptide which has been showed to have behavioral effects in human subjects, but does not have any steroidogenic effects, nor other significant side effects. This study was a double-blind, crossover trial of the ACTH4-9 analogue in four children with intractable seizures. There was some slight improvement in seizure frequency in two patients, with an equivocal improvement in a third child. A fourth child was unchanged, while the fifth dropped out of the study. There were no side effects from the therapy. This questionable improvement in seizure frequency in some of the most intractable patients with seizure disorders indicates the need to further assess this ACTH4-9 analogue in a larger study over a longer period of time.

Adrenocorticotropic Hormone↗
PubMed1999

Long-term hydroxyurea treatment in young sickle cell patients.

Hydroxyurea is the first drug that, under well-organized, large-scale trials in adults, has shown a beneficial effect on the clinical course of sickle cell disease. Several small-scale trials have been conducted in children, but they used different therapeutic schedules, and only one was a single-blind crossover trial. Still, children are clearly good responders to the treatment because a rapid clinical improvement was observed, with decreased frequencies of vaso-occlusive crises, acute chest syndromes, and transfusion requirements. Despite large interindividual variations, virtually all the children studied increased their fetal hemoglobin, mean corpuscular volume, and total hemoglobin. Follow-up varied from 6 months to 59 months. More than in adults, the fetal hemoglobin increase was sustained, and few side effects were observed. Large-scale, placebo-controlled studies seem no longer needed. Guidelines concerning patient selection, dosing schedules, and monitoring protocols as well as exhaustive registries for the detection of long-term side effects are necessary.

Adolescent↗
PubMed1984

Propanolol ('Inderal') in the treatment of childhood migraine.

In a double-blind crossover study of 39 children with established migraine, there was no difference between treatment with propanolol and placebo as regards frequency, severity or average duration of migraine attacks. There was some evidence that propanolol increased the average length of headaches.

Adolescent↗
PubMed1976

Comparative incidence of phlebitis due to buffered cephalothin, cephapirin, and cefamandole.

Buffered cephalothin, cefamandole, and cephapirin were compared with respect to their tendency to produce phlebitis. Two grams of each agent was administered every 6 h for 4 days to 12 healthy volunteers in a double-blind crossover fashion. Approximately 50% of intravenous sites developed mild (grade 1) phlebitis and 25% developed moderate (grade 2) phlebitis. The frequency of grade 1 inflammation did not differ significantly among the three cephalosporins. The proportion of individuals eventually exhibiting grade 2 phelebitis was highest with cefamandole, lowest with cephalothin (P = 0.07), and intermediate with cephapirin; however, cephapirin required a substantially greater number of doses to produce grade 2 phelebitis than did the other two drugs. These findings, together with the results of other reports, suggest that interpretation of the phlebitogenic potential of these antibiotics must be made with caution.

Adolescent↗
PubMed1976

Echophonocardiographic studies of the contribution of the atrioventricular valves to the first heart sound.

The movements of the mitral, tricuspid and aortic valves have been recorded echocardiographically and related to the first heart sound (S1) in patients with various hemodynamic and conduction abnormalities. Closure of the mitral and tricuspid valves has been studied with respect to the corresponding atrioventricular pressure crossover and it is clear that both valves finish closing about 50 msec after pressure crossover. In order to clarify the relative contribution of tricuspid valve closure and aortic root events to the second high frequency component of S1, a new simultaneous dual echophonocardiographic technique was employed. This permitted the simultaneous registration of tricuspid and aortic valve movements and demonstrated that in certain circumstances the second high frequency component of S1, could be attributed to tricuspid closure, aortic root events being excluded from the genesis of this sound. These observations suggest that the two high frequency components of S1 are related to closure of the mitral and tricuspid valves. The results do not however, exclude a contribution to S1 of aortic root events, which may be of lower frequency vibrations.

Aortic Valve↗
PubMed1982

"Biorhythms" and men's track and field world records.

The claims that athletic performance, like all human behavior, are governed by three invariant "biorhythms" were tested for all men's metric world records in track and field from 1913-1977 (N = 700). Outstanding performances are said to occur during positive cycle phases; and poor performances, errors of judgment, and accidents, during the negative phases and particularly at crossover points (critical days). "Biorhythm" amplitudes were calculated, and a chi-square (X2) analysis was used to compare the frequencies of records occurring in the positive, negative, and critical phases of each cycle with a random model. The phase-distribution of records within each individual cycle fit the random model (X2 less than or equal to 2.22, P greater than 0.30). The combined effects of the three cycles, determined from the mean "biorhythm" amplitude (X2 = 1.30, P greater than 0.20) and the number of cycles in each phase (X2 = 3.50, P greater than 0.30), also showed no significant departure from the expected frequencies. The number of records broken on single or multiple critical days was as expected from the number of critical days in ech cycle (X2 = 3.37, P greater than 0.15). These data reinforce our previous study on Australian records and the preponderance of acceptable published research into sports, accidents, and medical data in that they provide no evidence of the existence or effects of "biorhythms."

Circadian Rhythm↗
PubMed1987

Nifedipine in Raynaud's phenomenon: relationship between immediate, short term and longterm effects.

Sixteen patients with Raynaud's phenomenon (8 with primary Raynaud's, 8 with systemic sclerosis including 3 patients with CREST) were treated for 4 weeks in a double blind crossover study with nifedipine, 20 mg twice daily. Treatment resulted in improvement of symptoms (p less than 0.05), a lower frequency of attacks (p less than 0.05) and a tendency to a shorter duration of the attacks. Photoelectric plethysmography during nifedipine treatment showed greater amplitudes on cooling (p less than 0.05) and a better and faster recovery on rewarming (p less than 0.05) than during placebo. The immediate effect of nifedipine, 10 mg sublingually, on the amplitude of the plethysmogram, finger temperature, heart rate and blood pressure did not correlate with the effect of maintenance treatment. Dose titration based on therapeutic effect and side effects resulted in a dose of 20 mg daily for 5 patients, 40 mg for 7, and 80 mg daily for 3 patients. Longterm treatment (16-20 weeks) resulted in sustained efficacy, both by subjective and objective standards (plethysmography).

Adult↗
PubMed1995

[Opinion of asymptomatic HIV-positive patients about their primary care physicians].

OBJECTIVE: To find the opinion of asymptomatic HIV+patients about their Primary Care doctors. DESIGN: A descriptive, crossover study with an 11-item questionnaire, filled in by the patient him/herself anonymously and analysing: communication of being seropositive, frequency of attendance, confidence in the doctor and their competence in dealing with the patient. SETTING: AIDS Information and Prevention Centre, Alicante. PATIENTS: Consecutive sampling of the first 100 HIV+patients who attended voluntarily during the first 5 months of 1993 (from January 3 to May 18 inclusive). MEASUREMENTS: 60.2% (C.I. 95%, 69.9%--50.5%) said they communicated their being seropositive to the doctor. Intravenous drug users communicated this fact more (72.9%), against 41% of the rest of the groups (p = 0.0016). 25% had little or no confidence in their doctor and 44% considered him/her incompetent or barely competent, with these two variables being related (r = 0.42; p = 0.0001). Communicating their condition to the doctor is only related to more frequent attendance at the clinic (p = 0.0001). The reasons for not doing so are due mainly to lack of confidence (30.8%) and "didn't think of it" (46.2%). The doctor's competence obtained the lowest points average, 2.6, with its Confidence limits sharing no value with frequency of attendance or confidence. CONCLUSIONS: An important percentage of patients do not communicate their condition, due basically to problems of confidentiality and rejection. There are doubts among HIV+patients interviewed about their doctor's competence, at the same time as they have little confidence in him/her.

Adult↗
PubMed2006

Transient risk factors for acute traumatic hand injuries: a case-crossover study in Hong Kong.

OBJECTIVES: To identify the remediable transient risk factors of occupational hand injuries in Hong Kong in order to guide the development of prevention strategies. METHODS: The case-crossover study design was adopted. Study subjects were workers with acute hand injuries presenting to the government Occupational Medicine Unit for compensation claims within 90 days from the date of injury. Detailed information on exposures to specific transient factors during the 60 minutes prior to the occurrence of the injury, during the same time interval on the day prior to the injury, as well as the usual exposure during the past work-month was obtained through telephone interviews. Both matched-pair interval approach and usual frequency approach were adopted to assess the associations between transient exposures in the workplace and the short-term risk of sustaining a hand injury. RESULTS: A total of 196 injured workers were interviewed. The results of the matched-pair interval analysis matched well with the results obtained using the usual frequency analysis. Seven significant transient risk factors were identified: using malfunctioning equipment/materials, using a different work method, performing an unusual work task, working overtime, feeling ill, being distracted and rushing, with odds ratios ranging from 10.5 to 26.0 in the matched-pair interval analysis and relative risks ranging between 8.0 and 28.3 with the usual frequency analysis. Wearing gloves was found to have an insignificant protective effect on the occurrence of hand injury in both analyses. CONCLUSIONS: Using the case-crossover study design for acute occupational hand injuries, seven transient risk factors that were mostly modifiable were identified. It is suggested that workers and their employers should increase their awareness of these risk factors, and efforts should be made to avoid exposures to these factors by means of engineering and administrative controls supplemented by safety education and training.

Accidents, Occupational↗
PubMed1991

Multicenter controlled trial comparing high-frequency jet ventilation and conventional mechanical ventilation in newborn infants with pulmonary interstitial emphysema.

One hundred forty-four newborn infants with pulmonary interstitial emphysema were stratified by weight and severity of illness, and randomly assigned to receive treatment with high-frequency jet ventilation (HFJV) or rapid-rate conventional mechanical ventilation (CV) with short inspiratory time. If criteria for treatment failure were met, crossover to the alternate ventilatory mode was permitted. Overall, 45 (61%) of 74 infants met treatment success criteria with HFJV compared with 26 (37%) of 70 treated with CV (p less than 0.01). Eighty-four percent of patients who crossed over from CV to HFJV initially responded to the new treatment, and 45% ultimately met success criteria on HFJV. In contrast, only 9% of those who crossed over from HFJV to CV responded well to CV (p less than 0.01), and the same 9% ultimately met success criteria (p less than 0.05). Therapy with HFJV resulted in improved ventilation at lower peak and mean airway pressures, as well as more rapid radiographic improvement of pulmonary interstitial emphysema, in comparison with rapid-rate CV. Survival by original assignment was identical. When survival resulting from rescue by the alternate therapy in crossover patients was excluded, the survival rate was 64.9% for HFJV, compared with 47.1% for CV (p less than 0.05). The incidence of chronic lung disease, intraventricular hemorrhage, patent ductus arteriosus, airway obstruction, and new air leak was similar in both groups. We conclude that HFJV, as used in this study, is safe and is more effective than rapid-rate CV in the treatment of newborn infants with pulmonary interstitial emphysema.

Bronchopulmonary Dysplasia↗
PubMedDate not supplied

Severe hypoglycaemia in patients with type 1 diabetes and impaired awareness of hypoglycaemia: a comparative study of insulin lispro and regular human insulin.

OBJECTIVE: To assess the potential of insulin lispro to limit the frequency of severe hypoglycaemia without compromising glycaemic control in a cohort of patients with type 1 diabetes who are at a high risk of severe hypoglycemia. Research design and methods An open-label, randomised, 12-month comparative crossover study of insulin lispro and regular human insulin was performed in 33 patients with type 1 diabetes with impaired hypoglycaemia awareness. The efficacy of each treatment was evaluated by glycaemic control (HbA(1c)), eight-point home blood glucose profiles, and the frequency and severity of hypoglycaemic episodes and quality of life. RESULTS: Eighteen (55%) patients experienced one or more episodes of severe hypoglycaemia in the 48 weeks of study. There was a trend to a lower incidence of severe hypoglycaemia during treatment with insulin lispro in comparison with regular human insulin (55 vs 84 episodes, p=0.087). This resulted principally from a 47% lower incidence of nocturnal severe hypoglycaemia with insulin lispro (25 vs 47 episodes, p=0.11). The lower frequency of severe hypoglycaemia associated with insulin lispro was not explained by differences in glycated haemoglobin between insulin treatments (HbA(1c) 9.1% insulin lispro vs 9.3% regular human insulin). CONCLUSIONS: In individuals with type 1 diabetes, who have impaired awareness of hypoglycaemia, treatment with insulin lispro may be associated with a lower incidence of severe hypoglycaemia manifested predominantly through less frequent nocturnal episodes. Insulin lispro may have a beneficial role in the management of patients with diabetes at risk of severe hypoglycaemia, although a larger study is required to confirm these findings.

Adult↗
PubMed2002

Factors associated with non-fatal heroin overdose: assessing the effect of frequency and route of heroin administration.

AIMS: To examine risk factors associated with non-fatal heroin overdose, particularly frequency and route of heroin administration. DESIGN: Data from cross-sectional surveys were analysed as a case-control and as a case cross-over design. SETTING AND PARTICIPANTS: 2556 subjects treated for heroin dependence in 164 outpatient facilities in Spain. MEASUREMENTS: Prevalence of overdose involving emergency care in the 12 months before treatment admission. CASE CONTROL DESIGN: Odds ratio (OR) adjusted by logistic regression. CASE-CROSSOVER DESIGN: Estimated relative risk (RR) of transient risk of injecting heroin. FINDINGS: The prevalence of overdose was 10%. In the case control analysis the cumulative risk of overdose increased as the frequency of heroin use decreased. However, among daily heroin users this risk increased as the frequency of heroin injection rose, with an OR of 6.0 (95% CI: 3.9-9.6) for daily injectors versus non-injectors. Sniffers had a higher risk than smokers among non-daily users, but not among daily users. Other factors associated with increased risk of overdose were: tranquilizers, alcohol or cocaine use, living in certain regions and being long-term HIV+ 0. In the case-crossover analysis, the RR for injecting heroin versus using other routes immediately before overdose was 15.9 (95% CI: 9.5-26.6), and was much higher for non-daily heroin users than for daily users. CONCLUSIONS: These findings suggest that the rapid entry of a large quantity of heroin into the blood (as occurs when injecting) involves a high risk of overdose, especially when the heroin tolerance level is low (as occurs in sporadic users).

Adult↗
PubMed1997

Pectin and methyl cellulose do not affect intestinal function in patients after ileal pouch-anal anastomosis.

OBJECTIVES: Although ileal pouch-anal anastomosis is the procedure of choice for most patients with ulcerative colitis or familial adenomatous polyposis, most patients have problems with stool frequency and/or consistency. Although most clinicians recommend fiber supplementation for these patients, we could find no studies that prove the efficacy of this practice. The first purpose of this study was to document the effect of fiber supplementation on intestinal function in patients after ileal pouch-anal anastomosis. Because pectin, a soluble fiber supplement, has been reported to slow gastric and intestinal transit, we also hypothesized that pectin would be a superior fiber supplement in these patients. The second purpose, therefore, was to determine whether the effects of pectin on intestinal transit would result in decreased stool frequency in patients with an ileal pouch. METHODS: Thirteen patients who had undergone ileal pouch-anal anastomosis for ulcerative colitis were entered into a 9-wk crossover study. The protocol consisted of three 2-wk study periods, each of which was preceded by a 1-wk washout period. During the three study periods patients supplemented their diets, in random order, with Citrucel, 1 tablespoon twice daily; pectin, 1 tablespoon twice daily; or no supplement. Patients maintained detailed dietary and bowel function diaries. RESULTS: The effects (mean +/- SE) of Citrucel and pectin supplementation are summarized in Table 1. There was no significant effect of either supplement on stool frequency, pouch function, bloating, or stool consistency. In addition, there were no differences in continence. CONCLUSIONS: We found no evidence to support the common practice of fiber supplementation in patients with an ileal pouch. Furthermore, this study did not find that stool frequency decreased during supplementation with pectin. We conclude that there is little role for fiber supplementation in patients with an ileal pouch.

Adult↗
PubMed2001

Effect of a single-use sterile catheter for each void on the frequency of bacteriuria in children with neurogenic bladder on intermittent catheterization for bladder emptying.

OBJECTIVE: The frequency of bacteriuria is high in children with neurogenic bladder on intermittent catheterization for bladder emptying. In an effort to decrease bacteriuria, we examined whether the method of catheter care was responsible for the high rate of bacteriuria. For this, the frequency of bacteriuria was examined in the same patient on single-use sterile catheters and on reused clean catheters. METHODS: A prospective, randomized, crossover trial was conducted with 10 patients who were randomized to 4 months of a new, sterile catheter for intermittent catheterization and 4 months of reuse of a clean catheter for intermittent catheterization. Each week, a urine sample was collected and symptoms of infection and medication use were recorded. RESULTS: A total of 158 urine samples were collected during 164 patient-weeks on the new catheter method for each void; 115 (73%) were positive for a pathogen. Of the 161 samples collected during 169 patient-weeks on the standard, reuse method for voiding, 123 (76%) were positive (115 [73%] of 158 vs 123 [76%] of 161). Escherichia coli was the most common pathogen detected during both method periods. CONCLUSION: A new, sterile catheter for each void did not decrease the high frequency of bacteriuria in patients with neurogenic bladder on intermittent catheterization.

Adolescent↗
PubMed2005

Gene conversion tracts associated with crossovers in Rhizobium etli.

Gene conversion has been defined as the nonreciprocal transfer of information between homologous sequences. Despite its broad interest for genome evolution, the occurrence of this mechanism in bacteria has been difficult to ascertain due to the possible occurrence of multiple crossover events that would mimic gene conversion. In this work, we employ a novel system, based on cointegrate formation, to isolate gene conversion events associated with crossovers in the nitrogen-fixing bacterium Rhizobium etli. In this system, selection is applied only for cointegrate formation, with gene conversions being detected as unselected events. This minimizes the likelihood of multiple crossovers. To track the extent and architecture of gene conversions, evenly spaced nucleotide changes were made in one of the nitrogenase structural genes (nifH), introducing unique sites for different restriction endonucleases. Our results show that (i) crossover events were almost invariably accompanied by a gene conversion event occurring nearby; (ii) gene conversion events ranged in size from 150 bp to 800 bp; (iii) gene conversion events displayed a strong bias, favoring the preservation of incoming sequences; (iv) even small amounts of sequence divergence had a strong effect on recombination frequency; and (v) the MutS mismatch repair system plays an important role in determining the length of gene conversion segments. A detailed analysis of the architecture of the conversion events suggests that multiple crossovers are an unlikely alternative for their generation. Our results are better explained as the product of true gene conversions occurring under the double-strand break repair model for recombination.

Bacterial Proteins↗
PubMed1985

Effect of low oral doses of disopyramide and amiodarone on ventricular and atrial arrhythmias of chagasic patients with advanced myocardial damage.

Low-dose (7 mg/kg per day) disopyramide administration to arrhythmic chagasic patients decreased the frequency of ventricular extrasystoles in 4 of 17 patients (24%) and suppressed most complex ventricular arrhythmias in 12 of 15 patients (80%). This assessment was made from 72-h continuous Holter monitoring recorded during the course of this double blind, placebo-controlled randomized crossover study. Seven patients (41%) complained of anticholinergic side effects, but no contractile or conduction system depression was seen. Amiodarone (200 mg) given on a single blind, placebo-controlled basis to 9 of these patients reduced the frequency of ventricular extrasystoles in 6 of 9 patients (67%) and suppressed complex ventricular ectopy in 6 of 7 patients (85%). One patient was unable to tolerate this drug (11%). Both drugs seemed less effective in controlling supraventricular arrhythmias, although disopyramide eliminated paroxysms of supraventricular tachycardia in 9 of 13 (69%) and amiodarone in all 6 patients with this arrhythmia. Amiodarone appears to be a better antiarrhythmic drug for chagasic patients, due to its greater effectiveness and lower incidence of side effects.

Administration, Oral↗
PubMed1989

Distribution of meiotic recombination along nondisjunction chromosomes 21 in Down syndrome determined using cytogenetics and RFLP haplotyping.

Ten families (Down syndrome children and their parents) showing evidence of meiotic recombination between intraparental chromosomes transmitted after nondisjunction were studied. Cytogenetic polymorphisms and a cassette of RFLP markers distributed along chromosome 21 were used to analyze these families to localize the regions of meiotic recombination. Results indicated that only one crossover occurred per meiotic division and that nine of ten nondisjunctions appeared to be of maternal origin. In one family the crossover had taken place in the pericentromeric region, proximal to marker D21S13, which is quite exceptional. A chance of meiotic recombination within region 21q21, flanked by marker D21S72 and the amyloid gene, could be demonstrated in seven of the ten families. Most strikingly, this chance significantly decreased distal to q21, with frequencies of 0.3 and 0.1 in regions q22.2 and q22.3-qter, respectively. It is hypothesized that decreased chiasmata formation in the most distal part of chromosome 21q might promote nondisjunction. Furthermore, data from the ten crossovers made it possible to map provisionally two previously undefined markers, D21S24 and D21S82, to regions q21-qter and q22.1-qter, respectively.

Chromosome Banding↗