935 resultados para Double-blind Crossover


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The aim of this study was to evaluate the efficacy of a 0.05% clobetasol propionate ointment administered in trays to 22 patients with desquamative gingivitis in a double-blind, crossover, placebo-controlled trial. Patients received container number 1 and were instructed to apply the ointment 3 times a day for 2 weeks, and to reduce the application to once a day in the third week. Next, the patients were then instructed to discontinue the treatment for 2 weeks, and were then given container 2, used in the same way and for the same length of time as container 1. Regarding signs, 17 patients presented some improvement, while 5 experienced worsening with clobetasol propionate. With the placebo, 14 patients presented some improvement, and 8 patients presented worsening. For symptoms, there was complete improvement in 2 patients, partial improvement in 12, no response in 7, and worsening in 1 with clobetasol propionate. With the placebo, there was partial improvement in 8 patients, no response in 12 and worsening in 2. No statistically significant difference was found between clobetasol and placebo (p>0.05). Within the period designed to treat the gingival lesions of the patients, clobetasol propionate did not significantly outperform the placebo.

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Background: Galactooligosaccharides are selectively fermented by the beneficial member of the colonic microflora contributing to the health of the host. Objective: We assessed the prebiotic potential of a novel galactooligosaccharide produced through the action of beta-galactosidases, originating from a probiotic Bifidobacterium bifidum strain, against a galactooligosaccharide produced through the action of an industrial P-galactosidase and a placebo. Design: Fifty-nine healthy human volunteers participated in this study. Initially, the effect of the matrix on the prebiotic properties of a commercially available galactooligosaccharide (7 g/d) was assessed during 7-d treatment periods with a 7-d washout period in between. During the second phase, 30 volunteers were assigned to a sequence of treatments (7 d) differing in the amount of the novel galactooligosaccharide (0, 3.6, or 7 g/d). Stools were recovered before and after each intervention, and bacteria numbers were determined by fluorescent in situ hybridization. Results: Addition of the novel galactooligosaccharide mixture significantly increased the bifidobacterial population ratio compared with the placebo (P < 0.05), whereas 7 g/d of the novel galactooligosaccharide significantly increased the bifidobacterial ratio compared with the commercial galactooligosaccharide (P < 0.05). Moreover, a significant relation (P < 0.001) between the bifidobacteria proportion and the novel galactooligosaccharide dose (0, 3.6, and 7 g/d) was observed. This relation was similar to the effect of the novel galactooligosaccharide on the prebiotic index of each dose. Conclusions: This study showed that galactooligosaccharide mixtures produced with different beta-galactosidases show different prebiotic properties and that, by using enzymes originating from bifidobacterial species, an increase in the bifidogenic properties of the prebiotic product is achievable.

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BACKGROUND: The absorption of cocoa flavanols in the small intestine is limited, and the majority of the flavanols reach the large intestine where they may be metabolized by resident microbiota. OBJECTIVE: We assessed the prebiotic potential of cocoa flavanols in a randomized, double-blind, crossover, controlled intervention study. DESIGN: Twenty-two healthy human volunteers were randomly assigned to either a high-cocoa flavanol (HCF) group (494 mg cocoa flavanols/d) or a low-cocoa flavanol (LCF) group (23 mg cocoa flavanols/d) for 4 wk. This was followed by a 4-wk washout period before volunteers crossed to the alternant arm. Fecal samples were recovered before and after each intervention, and bacterial numbers were measured by fluorescence in situ hybridization. A number of other biochemical and physiologic markers were measured. RESULTS: Compared with the consumption of the LCF drink, the daily consumption of the HCF drink for 4 wk significantly increased the bifidobacterial (P < 0.01) and lactobacilli (P < 0.001) populations but significantly decreased clostridia counts (P < 0.001). These microbial changes were paralleled by significant reductions in plasma triacylglycerol (P < 0.05) and C-reactive protein (P < 0.05) concentrations. Furthermore, changes in C-reactive protein concentrations were linked to changes in lactobacilli counts (P < 0.05, R(2) = -0.33 for the model). These in vivo changes were closely paralleled by cocoa flavanol-induced bacterial changes in mixed-batch culture experiments. CONCLUSION: This study shows, for the first time to our knowledge, that consumption of cocoa flavanols can significantly affect the growth of select gut microflora in humans, which suggests the potential prebiotic benefits associated with the dietary inclusion of flavanol-rich foods. This trial was registered at clinicaltrials.gov as NCT01091922.

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In this placebo-controlled, double-blind, crossover human feeding study, the effects of polydextrose (PDX; 8 g/d) on the colonic microbial composition, immune parameters, bowel habits and quality of life were investigated. PDX is a complex glucose oligomer used as a sugar replacer. The main goal of the present study was to identify the microbial groups affected by PDX fermentation in the colon. PDX was shown to significantly increase the known butyrate producer Ruminococcus intestinalis and bacteria of the Clostridium clusters I, II and IV. Of the other microbial groups investigated, decreases in the faecal Lactobacillus–Enterococcus group were demonstrated. Denaturing gel gradient electrophoresis analysis showed that bacterial profiles between PDX and placebo treatments were significantly different. PDX was shown to be slowly degraded in the colon, and the fermentation significantly reduced the genotoxicity of the faecal water. PDX also affected bowel habits of the subjects, as less abdominal discomfort was recorded and there was a trend for less hard and more formed stools during PDX consumption. Furthermore, reduced snacking was observed upon PDX consumption. This study demonstrated the impact of PDX on the

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The aim of the study was to investigate the effects of acute supplementation of sodium bicarbonate (NaHCO3) on maximal accumulated oxygen deficit (MAOD) determined by a single supramaximal effort (MAODALT) in running and the correlation with 200- and 400-m running performances. Fifteen healthy men (age, 23 ± 4 years; maximal oxygen uptake, 50.6 ± 6.1 mL·kg(-1)·min(-1)) underwent a maximal incremental exercise test and 2 supramaximal efforts at 110% of the intensity associated with maximal oxygen uptake, which was carried out after ingesting either 0.3 g·kg(-1) body weight NaHCO3 or a placebo (dextrose) and completing 200- and 400-m performance tests. The study design was double-blind, crossover, and placebo-controlled. Significant differences were found between the NaHCO3 and placebo conditions for MAODALT (p = 0.01) and the qualitative inference for substantial changes showed a very likely positive effect (98%). The lactic anaerobic contribution in the NaHCO3 ingestion condition was significantly higher (p < 0.01) and showed a very likely positive effect (99% chance), similar to that verified for peak blood lactate concentration (p < 0.01). No difference was found for time until exhaustion (p = 0.19) or alactic anaerobic contribution (p = 0.81). No significant correlations were observed between MAODALT and 200- and 400-m running performance tests. Therefore, we can conclude that both MAODALT and the anaerobic lactic metabolism are modified after acute NaHCO3 ingestion, but it is not correlated with running performance.

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BACKGROUND: Petasin (Ze 339) was recently introduced on the market as a potent herbal antiallergic drug for treatment of respiratory allergies such as hay fever. Few clinical studies have been performed so far addressing the clinical effectiveness of Ze 339. OBJECTIVE: To evaluate the antiallergic properties of Ze 339 using skin prick tests with different stimuli, such as codeine, histamine, methacholine, and a relevant inhalant allergen. METHODS: A randomized, double-blind, placebo-controlled study was performed in which Ze 339 was compared to acrivastine, a short-acting antihistamine, in 8 patients with respiratory allergy and in 10 nonatopic, healthy volunteers. Antiallergic activity of Ze 339 was determined by analyzing inhibitory potency in skin prick tests with codeine, histamine, methacholine, and an inhalant allergen. Wheal-and-flare reactions were assessed 90 minutes after a double dose of Ze 339, acrivastine, or placebo. An interval of at least 3 days was left between the skin tests. RESULTS: Acrivastine was identified as the only substance that significantly inhibited skin test reactivity to all solutions analyzed in all study subjects. In contrast, no significant inhibition could be demonstrated for Ze 339 with any test solution. Moreover, the results of Ze 339 did not differ significantly from placebo. CONCLUSIONS: In this study we found no antiallergic, particularly antihistaminic, effect of Ze 339 in skin tests using a variety of stimuli often used to evaluate immediate skin test reactivity. The mechanism by which Ze 339 is effective in the treatment of seasonal allergic rhinitis still needs to be elucidated.

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The purpose of this study is to evaluate the effects of high doses of injected opiates as prescribed maintenance in intravenous drugs users. This was accomplished via a randomised double-blind study with crossover at an outpatient clinic in Bern, Switzerland. The subjects were 39 patients with a long history of intravenous opioid use and persistent abuse despite treatment; they were randomly allocated to two groups. Group A was started on controlled injection of graduated doses of morphine up to a satisfying individual dose and was then switched as a double blind to heroin at a randomly determined day between week three and four. Subsequently this group was given heroin for the remaining two to three weeks of the study. Group B was started on heroin and was then switched to morphine in the same manner. Equipotent solutions of 3% morphine and 2% heroin were administered. The main outcome measures were clinical observations, structural interviews and self report of subjective experiences to assess the effects of the drugs. In 16 cases, the study had to be discontinued owing to severe morphine-induced histamine reactions. Thirteen participants in Group B presented these adverse reactions on the day of the switch-over. Full data were thus only obtainable for 17 participants. Average daily doses were 491 mg for heroin and 597 mg for morphine. The findings indicate that heroin significantly produced a lower grade of itching, flushing, urticaria and pain/nausea. A negative correlation between dose and euphoria was observed for both heroin and morphine. The authors concluded that as heroin produces fewer side effects it is the preferred high-dose maintenance prescription to morphine. The perceived euphoric effects are limited in both substances.

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Although hypoalbuminaemia after injury may result from increased vascular permeability, dilution secondary to crystalloid infusions may contribute significantly. In this double-blind crossover study, the effects of bolus infusions of crystalloids on serum albumin, haematocrit, serum and urinary biochemistry and bioelectrical impedance analysis were measured in healthy subjects. Ten male volunteers received 2-litre infusions of 0.9% (w/v) saline or 5% (w/v) dextrose over 1 h; infusions were carried out on separate occasions, in random order. Weight, haemoglobin, serum albumin, serum and urinary biochemistry and bioelectrical impedance were measured pre-infusion and hourly for 6 h. The serum albumin concentration fell in all subjects (20% after saline; 16% after dextrose) by more than could be explained by dilution alone. This fall lasted more than 6 h after saline infusion, but values had returned to baseline 1 h after the end of the dextrose infusion. Changes in haematocrit and haemoglobin were less pronounced (7.5% after saline; 6.5% after dextrose). Whereas all the water from dextrose was excreted by 2 h after completion of the infusion, only one-third of the sodium and water from the saline had been excreted by 6 h, explaining its persistent diluting effect. Impedances rose after dextrose and fell after saline (P<0.001). Subjects voided more urine (means 1663 and 563 ml respectively) of lower osmolality (means 129 and 630 mOsm/kg respectively) and sodium content (means 26 and 95 mmol respectively) after dextrose than after saline (P<0.001). While an excess water load is excreted rapidly, an excess sodium load is excreted very slowly, even in normal subjects, and causes persistent dilution of haematocrit and serum albumin. The greater than expected change in serum albumin concentration when compared with that of haemoglobin suggests that, while dilution is responsible for the latter, redistribution also has a role in the former. Changes in bioelectrical impedance may reflect the electrolyte content rather than the volume of the infusate, and may be unreliable for clinical purposes.

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Glutathione (GSH) dysregulation at the gene, protein, and functional levels has been observed in schizophrenia patients. Together with disease-like anomalies in GSH deficit experimental models, it suggests that such redox dysregulation can play a critical role in altering neural connectivity and synchronization, and thus possibly causing schizophrenia symptoms. To determine whether increased GSH levels would modulate EEG synchronization, N-acetyl-cysteine (NAC), a glutathione precursor, was administered to patients in a randomized, double-blind, crossover protocol for 60 days, followed by placebo for another 60 days (or vice versa). We analyzed whole-head topography of the multivariate phase synchronization (MPS) for 128-channel resting-state EEGs that were recorded at the onset, at the point of crossover, and at the end of the protocol. In this proof of concept study, the treatment with NAC significantly increased MPS compared to placebo over the left parieto-temporal, the right temporal, and the bilateral prefrontal regions. These changes were robust both at the group and at the individual level. Although MPS increase was observed in the absence of clinical improvement at a group level, it correlated with individual change estimated by Liddle's disorganization scale. Therefore, significant changes in EEG synchronization induced by NAC administration may precede clinically detectable improvement, highlighting its possible utility as a biomarker of treatment efficacy. TRIAL REGISTRATION: ClinicalTrials.gov NCT01506765.

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The sedative and cardiovascular effects of rectally administered diazepam (0.6 mg/kg) were compared to placebo in uncooperative children who required sedation during dental treatment. Twelve healthy preschool children, who required amalgam restorations, were treated during two standardized restorative appointments in a double-blind, crossover study. Blood pressure and pulse were obtained during four specified intervals during the appointment. The behavior of the children during the treatment visits was videotaped and later statistically analyzed using a kinesics/vocalization instrument. Behavioral ratings of cooperation were significantly improved during the treatment visit following diazepam. All interfering bodily movements, patient vocalizations and operator commands for the diazepam group were reduced significantly (p≤0.0001). No significant differences were observed for noninterfering behavioral response. Rectally administered diazepam did not alter blood pressure or pulse significantly in these sedated children when compared to the placebo. These findings indicate that rectal diazepam is an effective sedative agent with minimal effect on the cardiovascular system for the management of the young pediatric dental patient.

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The pathophysiology of chronic fatigue syndrome (CFS) remains unclear; however, both biological and psychological factors have been implicated in establishing or maintaining this condition. People with CFS report significant and disabling cognitive difficulties such as impaired concentration that in some cases are exacerbated by exposure to chemical triggers. The aim of this study was to determine if neuropsychological deficits in CFS are triggered by exposure to chemicals, or perceptions about the properties of these substances. Participants were 36 people with a primary diagnosis of CFS, defined according to Centers for Disease Control (CDC) criteria. A randomized, double-blind, placebo-controlled, crossover design was used, with objective assessment of neuropsychological function and participant rating of substance type, before and after exposure to placebo or chemical trigger. Results showed decrements in neuropsychological tests scores on three out of four outcome measures when participants rated the substance they had been exposed to as chemical. No change in performance was found based on actual substance type. These results suggest that cognitive attributions about exposure substances in people with CFS may be associated with worse performance on neuropsychological tasks. In addition, these findings suggest that psychological interventions aimed at modifying substance-related cognitions may reduce some symptoms of CFS.

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Abstract INTRODUCTION: Previous studies have described improvements on lipid parameters when switching from other antiretroviral drugs to tenofovir (TDF) and impairments in lipid profile when discontinuing TDF. [1-3] It is unknown, however, if TDF has an intrinsic lipid-lowering effect or such findings are due to the addition or removal of other offending agents or other reasons. MATERIALS AND METHODS: RESULTS: 46 subjects with a median age of 43 (40-48) years were enrolled in the study: 70% were male, 56% received DRV/r and 44% LPV/r. One subject withdrew the study voluntarily at week 4 and another one interrupted due to diarrhoea at week 24. Treatment with TDF/FTC decreased total, LDL and HDL-cholesterol from 235.9 to 204.9 (p<0.001), 154.7 to 127.6 (p<0.001) and 50.3 to 44.5 mg/dL (p<0.001), respectively. In comparison, total, LDL and HDL-cholesterol levels remained stable during placebo exposure. Week 12 total cholesterol (p<0.001), LDL-cholesterol (p<0.001) and HDL-cholesterol (p=0.011) levels were significantly lower in TDF/FTC versus placebo. Treatment with TDF/FTC reduced the fraction of subjects with abnormal fasting total-cholesterol (≥200 mg/dL) from 86.7% to 56.8% (p=0.001) and LDL-cholesterol (≥130 mg/dL) from 87.8% to 43.9% (p<0.001), which was not observed with placebo. There were no virological failures, and CD4 and triglyceride levels remained stable regardless of exposure. CONCLUSION: Coformulated TDF/FTC has an intrinsic lipid-lowering effect, likely attributable to TDF.

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Objective: Studies suggest clinical benefit of glutamine-supplemented parenteral nutrition. The aim was to determine if the inclusion of 10 g of glutamine as part of the nitrogen source of home parenteral nutrition (HPN) reduces infectious complications. Subjects/Methods: Thirty-five patients on HPN were recruited and 22 completed the study. Patients were randomized to receive either standard HPN or glutamine-supplemented HPN. Patients were assessed at randomization, 3 and 6 months later then they were crossed over to the alternative HPN and reassessed at 3 and 6 months. Assessments included plasma amino acid concentrations, intestinal permeability and absorption, nutritional status, oral and parenteral intake, quality of life, routine biochemistry and haematology. Results: No difference was seen between the groups at randomization. No difference was detected between the treatment phases for infective complications (55% in the standard treatment phase and 36% in the glutamine-supplemented phase P 0.67). There were no differences in nutritional status, intestinal permeability, plasma glutamine concentrations or quality of life. Conclusion: Although limited by the sample size, the study has shown that glutamine as part of the nitrogen source of parenteral nutrition can be given to patients on HPN for 6 months without any adverse effects.

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Epidemiological studies have shown an inverse association between dietary intake of whole grains and the risk of chronic disease. This may be related to the ability to mediate a prebiotic modulation of gut microbiota. However, no studies have been conducted on the microbiota modulatory capability of whole-grain (WG) cereals. In the present study, the impact of WG wheat on the human intestinal microbiota compared to wheat bran (WB) was determined. A double-blind, randomised, crossover study was carried out in thirty-one volunteers who were randomised into two groups and consumed daily 48g breakfast cereals, either WG or WB, in two 3-week study periods, separated by a 2-week washout period. Numbers of faecal bifidobacteria and lactobacilli (the target genera for prebiotic intake), were significantly higher upon WG ingestion compared with WB. Ingestion of both breakfast cereals resulted in a significant increase in ferulic acid concentrations in blood but no discernible difference in faeces or urine. No significant differences in faecal SCFA, fasting blood glucose, insulin, total cholesterol (TC), TAG or HDL-cholesterol were observed upon ingestion of WG compared with WB. However, a significant reduction in TC was observed in volunteers in the top quartile of TC concentrations upon ingestion of either cereal. No adverse intestinal symptoms were reported and WB ingestion increased stool frequency. Daily consumption of WG wheat exerted a pronounced prebiotic effect on the human gut microbiota composition. This prebiotic activity may contribute towards the beneficial physiological effects of WG wheat.

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There is growing interest in the role of gastrointestinal (GI) pathology and clinical expression of autism. Recent studies have demonstrated differences in the faecal clostridial populations harboured by autistic and non-autistic children. The potential of Lactobacillus plantarum WCSF1 (a probiotic) to modulate the gut microbiota of autistic subjects was investigated during a double-blind, placebo-controlled, crossover-designed feeding study. The faecal microbiota, gut function and behaviour scores of subjects were examined throughout the 12-week study. Lactobacillus plantarum WCFS1 feeding significantly increased Lab158 counts (lactobacilli and enterococci group) and significantly reduced Erec482 counts (Clostridium cluster XIVa) compared to placebo. Probiotic feeding also resulted in significant differences in the stool consistency compared to placebo and behaviour scores (total score and scores for some subscales) compared to baseline. The major finding of this work was the importance of study protocol in relation to the specific considerations of this subject population, with an extremely high dropout rate seen (predominantly during the baseline period). Furthermore, the relatively high inter-individual variability observed suggests that subsequent studies should use defined subgroups of autistic spectrum disorders, such as regressive or late-onset autism. In summary, the current study has highlighted the potential benefit of L. plantarum WCFS1 probiotic feeding in autistic individuals.