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F Charles

Publications and source records attributed to F Charles.

35 records · Page 2Linked to original sources

Observation and properties of the X(3872) decaying to J/psipi(+)pi(-) in pp collisions at sqrt[s]=1.96 TeV.

We report the observation of the X(3872) in the J/psipi(+)pi(-) channel, with J/psi decaying to mu(+)mu(-), in pp collisions at sqrt[s]=1.96 TeV. Using approximately 230 pb(-1) of data collected with the Run II D0 detector, we observe 522+/-100 X(3872) candidates. The mass difference between the X(3872) state and the J/psi is measured to be 774.9+/-3.1(stat)+/-3.0(syst) MeV/c(2). We have investigated the production and decay characteristics of the X(3872) and find them to be similar to those of the psi(2S) state.

Journal Article↗

Search for doubly charged higgs boson pair production in the decay to mu(+)mu(+)mu(-)mu(-) in pp collisions at sqrt[s]=1.96 TeV.

A search for pair production of doubly charged Higgs bosons in the process pp -->H(++)H(--) -->mu(+)mu(+)mu(-)mu(-) is performed with the D0 run II detector at the Fermilab Tevatron. The analysis is based on a sample of inclusive dimuon data collected at an energy of sqrt[s]=1.96 TeV, corresponding to an integrated luminosity of 113 pb(-1). In the absence of a signal, 95% confidence level mass limits of M(H(+/-+/-)(L))>118.4 GeV/c(2) and M(H(+/-+/-)(R))>98.2 GeV/c(2) are set for left-handed and right-handed doubly charged Higgs bosons, respectively, assuming 100% branching into muon pairs.

Journal Article↗

SR 48692, a specific neurotensin receptor antagonist, has no effect on oesophageal motility in humans.

BACKGROUND: The administration of exogenous neurotensin can reduce the lower oesophageal sphincter pressure, but it is unclear whether this effect is pharmacological or physiological. AIM: A specific neurotensin receptor antagonist (SR 48692) was used to assess the effect of endogenous neurotensin on lower oesophageal sphincter function. METHODS: Twenty-four healthy male subjects were included in a double-blind, placebo-controlled, randomized, cross-over study designed to determine the effects of two single doses (90 and 300 mg, preceded by a loading dose) of SR 48692 on the resting lower oesophageal sphincter pressure, transient lower oesophageal sphincter relaxations, primary oesophageal peristalsis and oesophageal acid exposure. Oesophageal pH and motility recordings were performed during 1 h of fasting and 3 h post-prandially. Plasma neurotensin-like immunoreactivity release was determined by radioimmunoassay. RESULTS: During fasting, the lower oesophageal sphincter pressure, transient lower oesophageal sphincter relaxation rate and reflux episodes were similar with the two doses of SR 48692 and placebo. Meal ingestion induced a rise in plasma neurotensin-like immunoreactivity, a decrease in lower oesophageal sphincter pressure and an increase in both the transient lower oesophageal sphincter relaxation rate and the number of reflux episodes, which were not significantly modified by SR 48692. SR 48692 did not affect oesophageal primary peristalsis. CONCLUSION: This study shows that SR 48692, a specific neurotensin 1 receptor antagonist, has no effect on oesophageal motility in humans.

Cross-Over Studies↗

Experimental study of suspension-feeding activity in the serpulid polychaete Ditrupa arietina (O.F. Müller).

As time spent feeding can be an index of the feeding intensity, we attempted to describe the filtering activity in the suspension-feeding polychaete Ditrupa arietina. This description was based on the detection of the opening of the gill-crown by an automated image analysis system. The common pattern of activity could be described as the succession of filtering events and resting periods of which the number and the mean duration differed greatly from one worm to another. Filtering activity in D. arietina was neither a continuous process nor even a process having a particular rhythm. Within a same batch of worms, total filtration durations could represent between 12.5 and 87.5% of the total experimental time. Despite a strong inter-individual variability, our results showed the existence of pronounced seasonal variations in the activity of the gill-crown. In May, worms spent less than 25% of time feeding compared to more than 50% during the rest of year. These temporal changes appeared to result from the physiological state of the worms (reproductive period and ageing) at the time of the experiment.

Journal Article↗

Intrathecal anesthesia: ropivacaine versus bupivacaine.

We compared intrathecal ropivacaine to bupivacaine in patients scheduled for transurethral resection of bladder or prostate. Doses of ropivacaine and bupivacaine were chosen according to a 3:2 ratio found to be equipotent in orthopedic surgery. One hundred patients were randomly assigned to blindly receive either 10 mg of isobaric bupivacaine (0.2%, n = 50) or 15 mg of isobaric ropivacaine (0.3%, n = 50) over 30 s through a 27-gauge Quincke needle at the L2-3 level in the sitting position. Onset and offset times for sensory and motor blockades and mean arterial blood pressure were recorded. Pain at surgical site requiring supplemental analgesics was recorded. Cephalad spread of sensory blocks was higher with bupivacaine (median level, cold T(4) and pinprick T(7)) than with ropivacaine (cold T(6) and pinprick T(9)) (P<0.001). Eight patients in Group Ropivacaine received IV alfentanil (P<0.01). Onset time (mean +/- SD) to T(10) anesthesia and offset time at L2 were not different (bupivacaine = 13 +/-8 min, 127+/-41 min; ropivacaine = 11+/-7 min, 105+/-29 min). Complete motor blockade occurred in 43 patients with bupivacaine and in 41 patients with ropivacaine (not significant). Total duration of motor blockade was not different. No difference in hemodynamic effects was detected between groups. No patient reported back pain. We conclude that 15 mg of intrathecal ropivacaine provided similar motor and hemodynamic effects but less potent anesthesia than 10 mg of bupivacaine for endoscopic urological surgery.

Aged↗

Intrathecal bupivacaine in humans: influence of volume and baricity of solutions.

BACKGROUND: The effects of volume and baricity of spinal bupivacaine on block onset, height, duration, and hemodynamics were studied. METHODS: Ninety patients undergoing endoscopic urologic procedures were randomized to receive 10 mg of intrathecal bupivacaine at L2-L3 level in sitting position. In the operating room, commercial products were diluted as needed with NaCl 0.9% to obtain isobaric solutions (density, 1.005-1.008) or with NaC 10.9% and glucose 30% to obtain hyperbaric solutions (density, 1.031-1.037) of 2, 5, or 10 ml (six groups of 15 patients each). Three minutes after spinal injection the patients were placed in lithotomy position. Sensory blockade was assessed using pinprick and cold sensation tests, and motor blockade was assessed using a four-point scale. RESULTS: Onset times to maximal cephalad spread of spinal blockade were similar with isobaric and hyperbaric solutions. A greater maximal cephalad spread of anesthesia was obtained with diluted isobaric bupivacaine but was not associated with more hypotension. Volume had no effect on cephalad extent of anesthesia with hyperbaric bupivacaine. Times for regression of anesthesia to L2 and offset of motor block were longer with isobaric than with hyperbaric solutions of bupivacaine. The intensity of motor blockade was decreased with diluted hyperbaric bupivacaine. No patient reported back pain. CONCLUSION: In this study, volume had no significant influence on either cephalad spread or duration of sensory blockade for either isobaric or hyperbaric bupivacaine. Time for offset of anesthesia was shorter with hyperbaric bupivacaine compared with isobaric solutions.

Aged↗

Rapid gastric emptying in patients with functional diarrhea.

OBJECTIVE: To analyze our experience in patients with chronic diarrhea by using a noninvasive transit study that measures gastric emptying as well as small bowel and colonic transit. MATERIAL AND METHODS: Results from 94 consecutive transit tests, for which diarrhea was the main indication, were reviewed and correlated with the final classification of patients as having an organic or nonorganic disorder. RESULTS: Sixty patients were considered to have a nonorganic cause of diarrhea, of whom 15 had previously undergone cholecystectomy. The other 34 patients were considered to have diarrhea on the basis of an organic diagnosis. Gastric emptying was more often rapid in patients with a nonorganic cause (P < 0.05), but not if cholecystectomy had been performed previously. Small bowel transit was fast more often in patients with organic diarrhea than in those with no organic cause of the diarrhea (P < 0.05); colonic transits showed no significant differences among groups. CONCLUSION: The findings implicate a motor abnormality of the upper gut, rapid gastric emptying, as a pathophysiologic mechanism of functional bowel disorders with diarrhea. The results imply that additional prospective observations should be worth-while.

Adult↗

Effects of ethanol, xylose, and glucose on canine jejunal motility.

Ethanol is an important source of calories that can cause certain gastrointestinal symptoms, notably diarrhea. To examine the effects of ethanol on the small bowel, we intraluminally perfused the jejunum of four dogs with ethanol (18, 9, 4.5, and 1.5%, wt/vol), D-xylose (30, 15, 7.5, and 4.5%, wt/vol), or glucose (30 and 5%, wt/vol). In other experiments, these solutes were infused intravenously. Saline was always given by the alternate route; jejunal manometry was recorded during and after the infusions. Phase III of the interdigestive cycle was delayed by all intraluminal infusions except for 4.5 and 1.5% ethanol, 4.5% xylose, and 5% glucose. In addition, the onset of irregular contractile activity was delayed more with intraluminal ethanol than with intraluminal xylose or intraluminal glucose (P < 0.01). When administered intraluminally, ethanol and xylose appeared in blood but only ethanol equilibrated fully between the lumen and blood. Intravenous infusions of ethanol and xylose, but not glucose, also delayed the return of phase III. When given intravenously, ethanol and xylose were recovered from the lumen, whereas glucose never was. Ethanol and xylose had comparable effects on the canine small bowel; they induced prolonged periods of irregular contractile activity and delayed the return of phase III. These effects were seen rapidly when solutes were administered intraluminally and more slowly when they were given intravenously. These results suggest that local luminal mechanisms stimulated by solutes influence small bowel motility, and they imply that the gut recognizes solutes whether or not these molecules are metabolizable.

Animals↗

Scintigraphy of the whole gut: clinical evaluation of transit disorders.

OBJECTIVE: To describe an initial clinical experience with a noninvasive scintigraphic technique for assessing gastrointestinal motility. DESIGN: We studied gastric, small bowel, and colonic transit in 109 unselected patients encountered between June and December 1992 at the Mayo Clinic. MATERIAL AND METHODS: The study patients were categorized on the basis of major complaint (constipation in 46, upper gastrointestinal symptoms in 45, and diarrhea in 18) and presence or absence of an underlying organic disease. Radioscintigraphy was used to analyze various regions of the gastrointestinal tract; scans were obtained at 2, 4, 6, and 24 hours after ingestion of a radiolabeled test meal. RESULTS: Overall, patients with a main complaint of constipation usually had slow or normal gastric, small bowel, and colonic transit, whereas those with diarrhea as the major symptom usually had normal or fast results of these studies. In the 65 patients with no underlying organic disease, inconsistent patterns of gastric emptying and small bowel and colonic transit were noted. CONCLUSION: Our results suggest that this 24-hour scintigraphic test may be clinically useful in screening for dysmotility syndromes in patients with nausea, vomiting, diarrhea, or constipation.

Adolescent↗

Daytime ingestion of alcohol alters nighttime jejunal motility in man.

We studied the effects of acute ingestion of intoxicating doses of alcohol on jejunal motility in six male volunteers ages 24-45 who had two 24-hr ambulatory manometries, one week apart, that each included three standardized meals with either red wine (0.6 g of alcohol/kg) or dealcoholized wine. Breath alcohol was measured at regular intervals for 3 hr following alcohol. The results show that the MMC cycle was significantly (P < 0.01) shorter during the night than during the day in the "nonalcohol" group but not in the "alcohol" group and that the amplitude of contractions was higher during the night than the day in the alcohol group (P < 0.01). All meals interrupted the MMC and induced a fed pattern. After the 300-kcal liquid meal, the duration of the fed pattern was shorter (P < 0.01), with a lower motility index (P < 0.01) and fewer contractions (P < 0.01), than following the two 600-kcal meals. The number of clustered contractions occurring in the postprandial period was lower in the alcohol group than in the nonalcohol group. After the three alcohol doses, a breath alcohol peak was reached in 20-60 min, and in all subjects, breath alcohol fell below 22 micrograms/100 ml after the third hour. This study showed that alcohol had only minor effects on postprandial contractile activity but abolished the circadian variation of the MMC normally seen in healthy subjects. The fact that breath alcohol was low by the time of onset of sleep, suggests that the effects on the MMC may be mediated through central rather than local mechanisms.

Adult↗

Lipid metabolism by the intestinal mucosa in malnourished subjects following enteral nutrition supplemented with omega3 fatty acids.

UNLABELLED: Chronic malnutrition results in severe metabolic imbalance in man as the body modifies its modes of regulation of different nutrients, and in particular lipids. This study of the modifications in lipid metabolism induced by 15 days of enteral renutrition include: 12 malnourished patients (global nutritional deficit (GND) <20%) were given a cyclical enteral diet for 15 days under two conditions: ternary diet (Sondalis) or a similar diet whose lipid concentration was enriched by 5.3 g omega3 fatty acid per day. On Day 0 and Day 15, the serum lipid values were assayed and duodenal biopsies were taken to measure HMG-CoA reductase and (14)C acetate incorporation in the various classes of lipids. After 15 days of refeeding, the GND had been corrected by an average of 27% and HMG-CoA reductase activity had increased by 37% (60.2 +/- 7.46 vs 82.88 +/- 14.8 pmol/min/mg protein; p < 0.05). In 7 12 patients, the serum cholesterol values had increased (p < 0.01). No difference was observed in synthesis of FA, DG or cholesterol. Synthesis of phosphatidylcholines (PC) and phosphatidylglycerols (PG) was reduced by 12% and 23% respectively. Triglyceride synthesis (TG) increased by 20% (p < 0.05). The only difference between the two diets was in TG synthesis in organ-specific culture, which was increased only by the standard diet. IN CONCLUSION: (i) refeeding is accompanied by an increase in intestinal HMG-CoA reductase activity, a decrease in PC and PG synthesis, and an increase in TG synthesis; (ii) a diet enriched in omega3 FA increases TG synthesis less than the standard diet.

Journal Article↗