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PubMed1998

A comparison of selected nutrient intakes derived from three diet assessment methods used in a low-fat maintenance trial.

OBJECTIVE: In the vast majority of surveys and research in humans, dietary data are obtained from self-reports: recalls; records; or historical methods, usually food frequency questionnaires (FFQ). This study provides a rare opportunity to compare data derived from all three methods. DESIGN: A crossover study of dietary fat in which data were collected using an average of 11.4 food records and 11.7 24-h diet recalls. Using simple subtraction and correlation, energy and nutrient intakes derived from the three methods were compared to each other and with those derived from a single FFQ. Analysis of variance was used to evaluate sources of variability in nutrient intakes estimated from the individual days of records and recalls. SETTING: An independent, free-standing medical research institute. SUBJECTS: 13 men who were compliant with study procedures. RESULTS: FFQ-derived estimates of energy and nutrient intake were highest (e.g. 1967 kcal versus 1858 kcal and 1936 kcal for the records and recalls, respectively). Mean differences in energy and nutrient intakes and their variances were lowest and correlation coefficients highest in comparing the records and recalls (e.g. for fat the mean difference was 5.0 g, and r = 0.85). Analysis of variance of individual days of record- and recall-derived data (n = 300) revealed that there was no effect due to either method (record or recall) or the sequence of administration. CONCLUSIONS: Results of this study indicate that the FFQ overestimated dietary intake. Energy and nutrient results obtained from the records and recalls were interchangeable. However, based on smaller SDs around the means, it appears that the recalls may perform slightly better in estimating dietary intake in groups such as these well-educated, highly compliant men.

Analysis of Variance↗

PubMed1998

Audiometry in general practice: validation of a pragmatic pure-tone audiometry method.

The aim of this study was to validate the results of diagnostic pure-tone audiometry performed in a typical practice setting by comparing with test results obtained in a standardized audiological setting in accordance with the ISO standards. In a single-blinded crossover design, 119 persons were tested (0.25-8 kHz) in both settings. The mean deviations as a function of frequency were in the order of less than 2 dB (0.5-4 kHz) and otherwise up to 4 dB; the practice setting representing the poorer thresholds. The validity of the practice audiometry at three criteria of hearing impairment (0.5-4 kHz) was characterized by sensitivity (82-100%), specificity (95-99%); positive predictive values (75-90%) and negative predictive values (98-100%) focusing on the better ear. It is concluded that pure-tone audiometry of appropriate validity can be performed in general practice and that it is useful in selecting patients with no need of further audiological examination. Guidelines are needed.

Adult↗

PubMed2006

Linear and nonlinear hearing aid fittings--1. Patterns of benefit.

We evaluated the benefits of fast-acting WDRC, slow-acting AVC, and linear reference fittings for speech intelligibility and reported disability, in a within-subject within-device masked crossover design on 50 listeners with SNHL. Five hearing aid fittings were implemented having two compression channels and seven frequency bands. Each listener sequentially experienced each fitting for a 10-week period. Outcome measures included speech intelligibility under diverse conditions and self-reported disability. At a group level, each nonlinear fitting was superior to the linear references for benefits in listening comfort, listener satisfaction, reported intelligibility and speech intelligibility. Slow-acting AVC outperformed the fast-acting WDRC fittings for listening comfort, while for reported and measured speech intelligibility the converse was true. For listener satisfaction there were no group differences between the nonlinear fittings. Analysis in terms of fittings for individual listeners revealed subsets with definite divergences from the group data and hence a need for candidature criteria. There are systematic differences between the benefits of nonlinear and linear fittings, and also within nonlinear fittings with fast versus slow time constants. The patterns of benefit and individual optima depend on the domain of outcome being assessed.

Aged↗

PubMed1988

Treatment with acyclovir does not affect orogenital ulcers in Behçet's syndrome: a randomized double-blind trial.

Acyclovir is a potent antiviral drug, of proven efficacy in the treatment of herpes simplex virus infection. Since this virus has been implicated in the aetiology of Behçet's syndrome, the effect of acyclovir on orogenital ulceration in this condition was determined in a randomized, double-blind, placebo-controlled, crossover trial. Eighteen of 22 patients entering the study completed the trial. Treatment with acyclovir failed to alleviate the frequency and severity of orogenital ulceration or other disease features.

Adolescent↗

PubMed2005

Dynamics of nematic liquid crystal with quenched disorder in the random dilution and random field regimes.

By means of specific heat spectroscopy, we have studied the dynamics of nematic 8CB nucleated, in the presence of random disorder, as the temperature is lowered across the isotropic to nematic phase transition such that the crossover region of random dilution to random field regimes of disorder strength is explored. We show, in terms of frequency dependence, hysteretic behavior, and aging effects, that the out-of-equilibrium properties of the nematic nucleated in the random disorder regime are strongly reminiscent of the bulk material while the one grown in the random field regime shows a glassy behavior with aging leading to slower dynamics. The aging effect has been explained in terms of strain relaxation in analogy with observations in other soft glassy colloidal systems.

Liquid Crystals↗

PubMed1995

Intranasal insulin: the effects of three dose regimens on postprandial glycaemic profiles in type II diabetic subjects.

In both fasting normal and diabetic subjects, nasally administered insulin achieves significant falls in plasma glucose concentrations. Repeated administration before and during a meal has been necessary to lower postprandial glycaemic excursion in subjects with NIDDM. We have studied the use of Novolin Nasal which employs a non-irritant, lecithin-based enhancer as a vehicle for human insulin, on postprandial glucose profiles in NIDDM subjects to determine efficacy, optimal dose frequency, and tolerability. Seventeen NIDDM subjects (15 men, 2 women) participated in a randomized, partially blinded, placebo-controlled, crossover trial of three active treatment regimens (nasal insulin, 120 U at 0 min, 60 U at 0 and +20 min or 120 U at +20 min) in relation to a standardized mixed meal given at 0 min. All active treatments significantly reduced postprandial glucose concentrations compared to placebo. Intranasal insulin given at 0 min at a dose of 60 U or 120 U resulted in a 50% reduction in postprandial incremental glucose compared to placebo over the first 2 h, whereas treatment with 60 U both at 0 and 20 min lead to a 70% reduction over the 240 min postprandial period. Post-prandial intravenous insulin was the least effective. There were no episodes of symptomatic hypoglycaemia. Local tolerability was excellent with only four reports of transient nasal irritation out of a total of 68 doses. The delivery device was accurate with intra-device CV of delivered dose of 4.8%.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Intranasal↗

PubMed1976

Extrapyramidal effects of neuroleptics.

A study was conducted on 66 psychiatric inpatients who took major tranquilizers for periods of four to 16 years. The frequency of signs of Parkinsonism and the effects of orphenadrine on these were studied in a double-blind crossover method. Sixty-one per cent of the patients showed signs of Parkinsonism. Female patients and those with organic brain pathology more frequently exhibited Parkinsonism (although the difference was not statistically significant). No correlation was found between duration of treatment and extrapyramidal effects. Of the 40 patients who developed Parkinsonism, 25 responded favourably to orphenadrine, while six (15%) had more marked manifestations on orphenadrine than on placebo.

Adult↗

PubMed1989

Complotypes and extended haplotypes in laboratory medicine.

The region on the short arm of the sixth human chromosome encoding class I and class II histocompatibility antigens involved in immune recognition also encodes a group of molecules unrelated to HLA termed class III which includes C2, C4, and factor B. The four genes encoding the complement proteins occupy about 120 kb of genomic DNA between HLA-B and HLA-DR and are closer to HLA-DR. The four genes are inherited as a single unit, without observed crossover, called a complotype, designated by its BF, C2, C4A, and C4B alleles. There are about fifteen complotypes with frequencies of 0.01 or higher on normal caucasian chromosomes. Analysis of linkage disequilibrium between HLA-B, HLA-DR alleles, and complotypes reveals that about 30% of normal caucasian chromosomes consist of fixed sets called extended or fixed haplotypes. There are over a dozen such extended haplotypes defined by their HLA-B, DR and complotype alleles. They appear to contribute most of the previously described linkage disequilibrium between HLA-A/HLA-B and HLA-B/HLA-DR allelic pairs as well as most of the known HLA marker-disease associations. It is postulated that extended haplotypes consist of fixed DNA over at least the 10(6) base pairs of the HLA-B-DR interval, and independent examples in apparently unrelated individuals are thus identical or nearly identical over this interval. A practical consequence of this concept is the possible prediction of successful tissue transplantation donor-recipient pairs.

Chromosome Mapping↗

PubMed1995

[The structure of the chromocenter in the oocytes, the initiation of homologous pairing and the regulation of the formation of crossing over in Drosophila].

The structure of chromocenter and pairing of homologs in Drosophila oocytes with different X-chromosome inversions (sc7, sc9, BM1, y4, sc4sc8), and acrocentric compound C(1)DX were studied. Disturbances of chromosome pairing in compound C(1)DX, inversion of heterozygotes and some homozygotes (BM1, sc4sc8) were observed. Besides, disturbances of precentromeric heterochromatin regions pairing and nonassociation of X-bivalents with chromocenter were observed. It turned out that inversion loops were formed only in chromocenter formation peculiarities. It is supposed that disturbance of homologous pairing in inversion homozygotes is associated with transference of sites initiating the homologous pairing. These sites are in pretelomeric and adjacent heterochromatin regions. Interchromosomal effects of chromosome aberrations on crossingover and, probably, modification of its frequency by other factors are associated with the state of precentrometic heterochromatin homologous pairing in chromocenter. The formation of crossover exchanges is completed with a total pairing in these chromosome regions and subsequently with reorganization of the meiotic chromosome structure.

Animals↗

PubMed1996

Suppression of subclinical shedding of herpes simplex virus type 2 with acyclovir.

OBJECTIVE: To assess the effect of the antiviral drug acyclovir on the frequency of subclinical shedding of herpes simplex virus (HSV) in the genital tract. DESIGN: A double-blind, placebo-controlled, crossover clinical trial. SETTING: A university-based virology research clinic. PATIENTS: 34 women with herpes simplex virus type 2 (HSV-2) antibody only and genital herpes of less than 2 years' duration. INTERVENTION: Participants were randomly assigned to receive either acyclovir, 400 mg twice daily for 70 days, followed by a 14-day washout period, and then placebo for 70 days, or the study medications in the reverse order. MEASUREMENTS: Women collected daily genital swabs of the vulvar, cervicovaginal, and perianal areas for HSV culture, maintained a diary of genital lesions, and were examined at the time of recurrences. RESULTS: In an intent-to-treat analysis of the initial treatment period, 15 of the 17 women who received placebo and 3 of the 17 women who received acyclovir had at least 1 day of subclinical shedding (P < 0.001). Among the participants who received placebo, subclinical shedding occurred on 64 of 928 (6.9%) days compared with 3 of 1057 (0.3%) days among the participants who received acyclovir (P < 0.001). The relative risk for subclinical shedding was 0.09 (95% CI, 0.03 to 0.35) for the women who received acyclovir compared with the women who received placebo. In a paired analysis of 26 women who completed both arms of the study, acyclovir therapy was associated with a decrease in the frequency of subclinical shedding; subclinical shedding occurred on 83 of 1439 (5.8%) days with placebo, and on 6 of 1611 (0.37%) days with acyclovir (P < 0.001)--a 94% reduction. The frequency of subclinical shedding was reduced at all anatomic sites and in all patients. CONCLUSIONS: Daily therapy with oral acyclovir suppresses subclinical shedding of HSV-2 in the genital tract, suggesting that studies to evaluate the use of acyclovir in preventing HSV-2 transmission are warranted.

Acyclovir↗

PubMed2004

Placebo-controlled study on efficacy and safety of daily apomorphine SL intake in premenopausal women affected by hypoactive sexual desire disorder and sexual arousal disorder.

OBJECTIVES: To verify whether apomorphine SL is effective in premenopausal women affected by arousal disorder with hypoactive sexual desire disorder. METHODS: Sixty-two volunteer women, aged 26 to 45 years, affected by arousal disorders and hypoactive sexual desire disorder participated in the study, which consisted of two parts. The first was 4 weeks of a taken-as-needed, open-label, dose-escalation regimen starting at 2 or 3 mg of apomorphine SL. The second part of the study was for the nonresponders, who were randomly allocated to treatment in one of six possible sequences of three 2-week double-blind, crossover study periods with apomorphine 2 mg or 3 mg, washout, and placebo. Efficacy was assessed with the Personal Experiences Questionnaire using the 5-point Likert scale. The Personal Experiences Questionnaire quantified subjective arousal, desire, orgasm, enjoyment, and frequency of sexual relationships. RESULTS: Fifty women completed the 4-week "as required" drug regimen, and 6 of them benefited from this treatment regimen (P <0.05). The 44 women who reported no change with respect to baseline participated in the double-blind crossover part of the study. Six women stopped taking the drug because of a fear of problems (two each during the 2-mg apomorphine, 3-mg apomorphine, and placebo periods). Adverse events were mild or moderate, both occurred during the "as required" part (10 patients) and during daily usage (6 patients) and were mainly nausea, vomiting, dizziness, or headache. However, during the placebo period, 2 women had adverse events, mainly headache. The daily intake of the drug was effective with both the 2-mg and 3-mg dosages compared with placebo for arousal and desire (P <0.05). The effects of 3 mg of apomorphine were better than those obtained with 2 mg (P <0.05). The orgasm, enjoyment, and satisfied by frequency scores improved during treatment with daily apomorphine compared with baseline and placebo. CONCLUSIONS: The results of our study suggest that daily apomorphine SL may improve the sexual life of women affected by sexual difficulties. Additional studies are needed to define the daily use of apomorphine SL in large subgroups of women on the basis of etiology and the severity of sexual dysfunction.

Adult↗

PubMed2001

Cis-acting sequences may contribute to size variation in the surface glycoprotein of bovine immunodeficiency virus.

Genetic recombination is an important mechanism of retrovirus variation and diversity. Size variation in the surface (SU) glycoprotein, characterized by duplication and insertion, has been observed during in vivo infection with several lentiviruses, including bovine immunodeficiency virus (BIV), equine infectious anaemia virus (EIAV) and human immunodeficiency virus type 1. These duplication/insertion events are thought to occur through a mechanism of template switching/strand transfer during reverse transcription. Studies of RNA recombination in a number of virus systems indicate that cis-acting sequences can modulate the frequency of template switching/strand transfer. The size variable region of EIAV and BIV SU glycoproteins was examined and an AU-rich region and regions of nucleotide sequence identity that may facilitate template switching/strand transfer were identified. An in vitro strand transfer assay using donor and acceptor templates derived from the size variable region in BIV env detected both precise and imprecise strand transfer products, in addition to full-length products. Sequence analysis of clones obtained from imprecise strand transfer products showed that 87.5% had crossover sites within 10 nt of the crossover site observed in vivo. Mutations in the donor template which altered either the AU-rich region or nucleotide sequence identity dramatically decreased the frequency of imprecise strand transfer. Together, these results suggest that cis-acting elements can modulate non-homologous recombination events during reverse transcription and may contribute to the genetic and biological diversity of lentiviruses in vivo.

Amino Acid Sequence↗

PubMed2005

Gene conversion and deletion frequencies during double-strand break repair in human cells are controlled by the distance between direct repeats.

Homologous recombination (HR) repairs DNA double-strand breaks and maintains genome stability. HR between linked, direct repeats can occur by gene conversion without an associated crossover that maintains the gross repeat structure. Alternatively, direct repeat HR can occur by gene conversion with a crossover, or by single-strand annealing (SSA), both of which delete one repeat and the sequences between the repeats. Prior studies of different repeat structures in yeast and mammalian cells revealed disparate conversion:deletion ratios. Here, we show that a key factor controlling this ratio is the distance between the repeats, with conversion frequency increasing linearly with the distances from 850 to 3800 bp. Deletions are thought to arise primarily by SSA, which involves extensive end-processing to reveal complementary single-strands in each repeat. The results can be explained by a model in which strand-invasion leading to gene conversion competes more effectively with SSA as more extensive end-processing is required for SSA. We hypothesized that a transcription unit between repeats would inhibit end-processing and SSA, thereby increasing the fraction of conversions. However, conversion frequencies were identical for direct repeats separated by 3800 bp of transcriptionally silent or active DNA, indicating that end-processing and SSA are not affected by transcription.

Animals↗

PubMed2005

The effect of dosing frequency on the pharmacokinetics of a fentanyl HCl patient-controlled transdermal system (PCTS).

INTRODUCTION: The fentanyl HCl patient-controlled transdermal system (PCTS) is a noninvasive, needle-free, credit card-sized drug delivery system designed for the on-demand management of acute pain in a medically supervised setting. The objective of these studies was to determine the effect of dosing frequency on the pharmacokinetics of fentanyl delivered by the PCTS. METHODS: All three studies were single-centre, open-label, randomised, crossover studies. The fentanyl HCl PCTS was applied to the upper outer arm of all participants. In the first study, participants (n = 30) received three fentanyl HCl PCTS 25 microg treatments: two sequential doses hourly for 23.33 hours, six sequential doses every 3 hours for 22 hours, and 72 doses continuously over 12 hours. Participants (n = 31) in the second study received three fentanyl HCl PCTS 40 microg treatments: two sequential doses hourly over 23.33 hours, six sequential doses every 3 hours over approximately 10 hours, and 80 doses continuously over 13.33 hours. In the third study, participants (n = 28) received four fentanyl HCl PCTS 40 microg treatments: 6, 18, 36 and 80 doses over 1, 3, 6 and 13.33 hours, respectively. Naltrexone was used to block the opioid effects of fentanyl. Pharmacokinetic parameters, including maximum serum fentanyl concentration (Cmax), time to Cmax (tmax), area under the serum concentration-time curve (AUC) and terminal half-life (t(1/2)) were determined. RESULTS: In the first study, the dose-normalised AUC (AUCn) values for the 2- and 6-dose sequence treatments were not significantly different (p = 0.937), suggesting that the frequency of dosing has little effect on the amount of fentanyl absorbed; however, the AUCn for the 72-dose treatment was significantly lower than that of the other treatments (p = 0.001), which were of longer duration. The results of the second study paralleled those from the first, suggesting that the bioavailability of fentanyl delivered by the PCTS increases as a function of time and is likely to be independent of dosing frequency. Results from the third study suggested that approximately 40% of the nominal 40 microg fentanyl dose is absorbed during the first hour of treatment, with the full nominal dose absorbed after approximately 10 hours. The fentanyl HCl PCTS was well tolerated. CONCLUSION: The amount of fentanyl absorbed from the PCTS increases as a function of time and is independent of both dosing frequency and total number of doses delivered. The fentanyl HCl PCTS is generally safe and well tolerated.

Administration, Cutaneous↗

PubMed2002

Drug treatments for obstructive sleep apnoea.

BACKGROUND: The treatment of choice for moderate to severe obstructive sleep apnoea (OSA) is continuous positive airway pressure (CPAP) via a mask during sleep. However this is not tolerated by all patients and its role in mild OSA is not proven. Drug therapy has been proposed as an alternative to CPAP in some patients with mild to moderate sleep apnoea. The mechanisms by which drugs might reduce OSA include; a reduction in the proportion of rapid eye movement (REM) sleep (during which apnoeas tend to be more frequent), an increase in ventilatory drive or an increase in upper airway muscle tone during sleep. OBJECTIVES: To determine the efficacy of drug therapies in the treatment of sleep apnoea. SEARCH STRATEGY: Searches were carried out on the Cochrane Airways Group RCT Register. Additional hand searching was performed as relevant. SELECTION CRITERIA: Double blind, randomised placebo controlled trials were included, involving patients with confirmed obstructive sleep apnoea. Trials were excluded if continuous positive airways pressure, mandibular devices or oxygen therapy were used. No restriction was placed upon publication language or trial duration. DATA COLLECTION AND ANALYSIS: A total of 51 references were identified by electronic searches. 42 studies were retrieved for selection and 9 trials were included in the review. The results for 91 patients were available. No response for further information was forthcoming from the study authors. Results were expressed as (WMD) and 95% Confidence Intervals (95% CI) MAIN RESULTS: Only acetazolamide reduced the Hypopnoea Index (1 crossover trial of 9 patients, Weighted Mean Difference -24; 95%Confidence Intervals (95% CI): -4, -44). However there was no symptomatic response and the drug was poorly tolerated. Protriptyline led to a symptomatic improvement (improved vs not improved) in two out of three crossover trials (13 patients, Peto Odds Ratio 29.2; 95%CI 2.8, 301.1) but there was no change in the apnoea frequency. No beneficial effects were found for medroxy progesterone, clonidine, buspirone, aminophylline, theophylline or sabeluzole. REVIEWER'S CONCLUSIONS: The data available do not support the use of drugs as a therapy for OSA. Although the studies examined had limitations there was little to justify further trials of these particular drugs.

Humans↗

PubMed1976

Genetic recombination of Coprinus. V. Repair synthesis of deoxyribonucleic acid and its relation to meiotic recombination.

Repair synthesis of DNA per se at pachytene is not needed for commitment to meiotic recombination although it is a necessary event to follow. Recombination frequency is governed by the rate of nicking and the time in which unrepaired nicks are allowed to match and crossover. Cold treatment at pachytene prevented repair synthesis, hence open nicks were accumulated to match and crossover, and a 3-fold increase in recombination resulted. The kinetics of cold temperature effect followed a quadratic function as shown by a computer simulation which agreed with our experimental data (Lu, 1974b). High temperature did not change the rate of repair synthesis. It did cause an increased nicking which led to a twofold increase in recombination and which entailed a higher rate of recovery repair synthesis.

Agaricales↗

PubMed1989

Bioequivalent doses of budesonide and prednisone in moderate and severe asthma.

We determined the relative antiasthmatic and systemic glucocorticoid potencies of inhaled budesonide (BUD) versus morning-dose oral prednisone (PRED) in 34 adult patients with asthma over a dose range extending from conventional to high and potentially toxic levels, 3.2 mg of BUD or 40 mg of PRED per day. Changes in symptom frequency and severity, FEV1, and peak expiratory flow rate were measured during a double-blind, double-dummy controlled, crossover protocol. The drugs proved equally effective, provided a sufficient dosage was administered. The dose required to eliminate recurrently disabling asthma relapses in these patients was about 2.0 mg of BUD per day or greater than 40 mg of PRED per day. On the average, BUD doses greater than or equal to 1.84 mg/day/70 kg adult (26.3 micrograms/kg/day) exhibited systemic effects on the 8 AM serum cortisol level and blood eosinophil count equivalent to greater than or equal to 15 mg of PRED per day. The latter doses are known to be associated with steroid-induced complications, such as osteoporosis. However, the level of systemic glucocorticoid activity produced by any particular dose of BUD in these patients was consistently much lower than that produced by the dose of PRED needed to achieve an equivalent level of antiasthmatic response. Thus, the use of high-dose inhaled BUD appears clinically reasonable and ethically acceptable in patients with severe asthma in whom the alternative is their continuing dependency on PRED.

Administration, Inhalation↗

PubMed1990

Efficient integrative transformation of the phytopathogenic fungus Alternaria alternata mediated by the repetitive rDNA sequences.

An attempt was made to transform Alternaria alternata protoplasts using a plasmid vector, pDH25, bearing the Escherichia coli hygromycin B (Hy) phosphotransferase gene (hph) under the control of the Aspergillus nidulans trpC promoter. Transformants arose on a selective medium containing 100 micrograms Hy/ml. There were two types of transformants, forming large and small colonies on the selective medium. Transformation with one microgram of the vector produced an average of 4.5 large colonies and 600 small ones. In large-colony transformants, the vector often integrated into the recipient chromosome in the form of highly rearranged tandem arrays. To increase transformation efficiency, fragments of the highly repetitive ribosomal RNA gene cluster (rDNA) of A. alternata were used to construct four new vectors for homologous recombination system. Use of these vectors gave higher transformation efficiency than the original plasmid. The best vector, pDH25r1a, gave rise to large-colony transformants at a frequency 20 times higher than pDH25. Transformation events in A. alternata with pDH25r1a occurred by homologous recombination as a single crossover between the plasmid-borne rDNA segment and its homologue in the chromosome, often giving rise to tandemly repeated vector DNA.

Alternaria↗