88 resultados para intermittent


Relevância:

10.00% 10.00%

Publicador:

Resumo:

INTRODUCTION: Perioperative hypovolemia arises frequently and contributes to intestinal hypoperfusion and subsequent postoperative complications. Goal-directed fluid therapy might reduce these complications. The aim of this study was to compare the effects of goal-directed administration of crystalloids and colloids on the distribution of systemic, hepatosplanchnic, and microcirculatory (small intestine) blood flow after major abdominal surgery in a clinically relevant pig model. METHODS: Twenty-seven pigs were anesthetized and mechanically ventilated and underwent open laparotomy. They were randomly assigned to one of three treatment groups: the restricted Ringer lactate (R-RL) group (n = 9) received 3 mL/kg per hour of RL, the goal-directed RL (GD-RL) group (n = 9) received 3 mL/kg per hour of RL and intermittent boluses of 250 mL of RL, and the goal-directed colloid (GD-C) group (n = 9) received 3 mL/kg per hour of RL and boluses of 250 mL of 6% hydroxyethyl starch (130/0.4). The latter two groups received a bolus infusion when mixed venous oxygen saturation was below 60% ('lockout' time of 30 minutes). Regional blood flow was measured in the superior mesenteric artery and the celiac trunk. In the small bowel, microcirculatory blood flow was measured using laser Doppler flowmetry. Intestinal tissue oxygen tension was measured with intramural Clark-type electrodes. RESULTS: After 4 hours of treatment, arterial blood pressure, cardiac output, mesenteric artery flow, and mixed oxygen saturation were significantly higher in the GD-C and GD-RL groups than in the R-RL group. Microcirculatory flow in the intestinal mucosa increased by 50% in the GD-C group but remained unchanged in the other two groups. Likewise, tissue oxygen tension in the intestine increased by 30% in the GD-C group but remained unchanged in the GD-RL group and decreased by 18% in the R-RL group. Mesenteric venous glucose concentrations were higher and lactate levels were lower in the GD-C group compared with the two crystalloid groups. CONCLUSIONS: Goal-directed colloid administration markedly increased microcirculatory blood flow in the small intestine and intestinal tissue oxygen tension after abdominal surgery. In contrast, goal-directed crystalloid and restricted crystalloid administrations had no such effects. Additionally, mesenteric venous glucose and lactate concentrations suggest that intestinal cellular substrate levels were higher in the colloid-treated than in the crystalloid-treated animals. These results support the notion that perioperative goal-directed therapy with colloids might be beneficial during major abdominal surgery.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background: Classical Roux-en-Y gastric bypass (cRYGB) is a combined restrictive and slightly malabsorptive operation. Excess-BMI-loss (EBMIL) in cRYGB is ~60%, but is diminished for super obese patients (BMI > 50 kg/m2). We therefore designed a modified, mainly malabsorptive distal RYGB (dRYGB). Methods: We report mid-term results after 77 consecutive dRYGB in which malabsorption is inversely related to the length of the common channel. The common channel was 100–150 cm long depending on preoperative BMI, the biliopancreatic limb was 100 cm long, which left >>250 cm for the alimentary channel. To avoid the potentially dangerous combination of malabsorption with sustained restriction the pouch size was increased to ~50ml and a 25 mm circular stapler was used for the gastro-jejunostomy. Results: 33 open and later on 44 laparoscopic interventions have been performed. Median preoperative BMI was 50.2 kg/m 2. No severe intraoperative complications have been observed and no anastomotic leakage was noted in the postoperative period. 5 patients needed balloon dilation of an anastomotic stricture. 3 marginal ulcers occurred at the gastrojejunostomy. The 54 patients with a follow-up time of over 12 months (median 24 months) showed an overall median BMI-reduction of 17 to an actual median BMI of 31.6 kg/m2, corresponding to a EBMIL of 74.5%. Obesity-related comorbid conditions were significantly reduced or cured. Intermittent diarrhea or steatorrhea in 12 patients was easily treated by pancreatic enzyme supplementation. Conclusion: dRYGB is technically more demanding than cRYGB, but shows excellent results in terms of weight-loss and therefore also in reduction of comorbidity especially in super-obese patients. Measuring all three limb lengths allows for a calibration of the malabsorption. The quality of food-intake being important to (super-) obese patients in terms of quality of life, a less restrictive pouch seems more adapted to them. Lifelong multidisciplinary follow-up is mandatory.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

BACKGROUND: Exposure to intermittent magnetic fields of 16 Hz has been shown to reduce heart rate variability, and decreased heart rate variability predicts cardiovascular mortality. We examined mortality from cardiovascular causes in railway workers exposed to varying degrees to intermittent 16.7 Hz magnetic fields. METHODS: We studied a cohort of 20,141 Swiss railway employees between 1972 and 2002, including highly exposed train drivers (median lifetime exposure 120.5 muT-years), and less or little exposed shunting yard engineers (42.1 muT-years), train attendants (13.3 muT-years) and station masters (5.7 muT-years). During 464,129 person-years of follow up, 5,413 deaths were recorded and 3,594 deaths were attributed to cardio-vascular diseases. We analyzed data using Cox proportional hazards models. RESULTS: For all cardiovascular mortality the hazard ratio compared to station masters was 0.99 (95%CI: 0.91, 1.08) in train drivers, 1.13 (95%CI: 0.98, 1.30) in shunting yard engineers, and 1.09 (95%CI: 1.00, 1.19) in train attendants. Corresponding hazard ratios for arrhythmia related deaths were 1.04 (95%CI: 0.68, 1.59), 0.58 (95%CI: 0.24, 1.37) and 10 (95%CI: 0.87, 1.93) and for acute myocardial infarction 1.00 (95%CI: 0.73, 1.36), 1.56 (95%CI: 1.04, 2.32), and 1.14 (95%CI: 0.85, 1.53). The hazard ratio for arrhythmia related deaths per 100 muT-years of cumulative exposure was 0.94 (95%CI: 0.71, 1.24) and 0.91 (95%CI: 0.75, 1.11) for acute myocardial infarction. CONCLUSION: This study provides evidence against an association between long-term occupational exposure to intermittent 16.7 Hz magnetic fields and cardiovascular mortality.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

BACKGROUND: There is a lack of studies about how to proceed surgically in rare strabismus diseases. It was the aim of this study to inteview experienced German-speaking strabismologists about how they perform surgery in rare but also some frequent strabismic conditions. The focus was on the choice of the technique, the timing, and the dosage. METHOD: A validated questionnaire was sent to 11 experienced strabismus surgeons. It contained questions about the following topics: congenital fibrosis syndrome, Jaentsch-Brown syndrome, intermittent exotropia, maximum dosage for rectus muscle surgery, Kestenbaum surgery, sixth nerve palsy, heterophorias, myokymia of the superior oblique muscle, thyroid endocrine orbitopathy, dissociated vertical deviation, adjustable sutures, advancement of previously recessed rectus muscles, retroequatorial myopiexia, and congenital esotropia. RESULTS: Ten experts answered the questionnaire (91 %). There was a large consent for many topics. However, for many procedures there was disagreement about the dosage and the timing. Since some questions addressed rare diseases and many strabismologists use only certain types of surgical procedures, some questions could only be answered by a few surgeons. CONCLUSIONS: German-speaking strabismologist show a large consensus about the type of surgical procedure to use, but often disagree about the dosage and timing of the operation.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Repeated exposure to psychomotor stimulants produces a striking behavioral syndrome involving repetitive, stereotypic behaviors that occur if an additional exposure to the stimulant is experienced. The same stimulant exposure produces specific alterations in gene expression patterns in the striatum. To identify the dopamine receptor subtypes required for the parallel expression of these acquired neural and behavioral responses, we treated rats with different D1-class and D2-class dopamine receptor agonists and compared the responses of drug-naive rats with those of rats given previous intermittent treatment with cocaine. In rats exposed to repeated cocaine treatment, the effects of a subsequent challenge treatment with either a D1-class agonist (SKF 81297) or a D2-class agonist (quinpirole) were not significantly different from those observed in drug-naive animals: the drugs administered singly did not induce robust stereotyped motor behaviors nor produce significantly striosome-predominant expression of early genes in the striatum. In contrast, challenge treatment with the D1-class and D2-class agonists in combination led to marked and correlated increases in stereotypy and striosome-predominant gene expression in the striatum. Thus, immediately after repeated psychomotor stimulant exposure, only the concurrent activation of D1 and D2 receptor subclasses evoked expression of the neural and behavioral phenotypes acquired through repeated cocaine exposure. These findings suggest that D1-D2 dopamine receptor synergisms underlie the coordinate expression of both network-level changes in basal ganglia activation patterns and the repetitive and stereotypic motor response patterns characteristic of psychomotor stimulant sensitization.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

BACKGROUND: Nail involvement is known as a common finding in psoriatic patients and represents a significant impact on patients' quality of life. The treatment of nail psoriasis is often challenging, and there is a need for new therapeutic options. Biologicals effective in the treatment of moderate to severe chronic plaque psoriasis may represent a new therapeutic modality for this disease. Adalimumab is a fully human IgG1 monoclonal antibody that binds to tumor necrosis factor alpha with high affinity and specificity. OBSERVATIONS: We report two cases of rapid improvement in nail psoriasis under adalimumab monotherapy with maintained effectiveness despite intermittent treatment as well as long remission after therapy discontinuation. CONCLUSION: The marked improvement of our two cases indicates that adalimumab may also help ameliorate nail psoriasis and warrants further controlled studies to establish the effectiveness and therapeutic regimes.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

BACKGROUND: Exhaled nitric oxide (FENO) is a marker for allergic airway inflammation. We wondered whether in patients with intermittent allergic rhinitis only (i) natural pollen exposure and (ii) artificial pollen exposure by repeated nasal allergen provocations may lead to an elevation of FENO. METHODS: In two prospective studies, we compared the FENO of nonatopic controls with the FENO of nonasthmatic individuals with mild intermittent rhinitis to tree and/or grass pollen. Study I: 13 atopic individuals and seven controls had measurements of FENO, blood eosinophils and eosinophilic cationic protein (ECP) before, during and after pollen season. Study II: 16 atopic individuals and 12 controls had nasal allergen provocations on four following days out of pollen season, with daily measurements of FENO before, 2 and 6 h after provocation, and determination of blood eosinophils, ECP and FEV1 at baseline, on days 5 and 10-12. RESULTS: Natural pollen exposure (study I) caused a significant elevation of FENO in allergic individuals. Nasal allergen provocations (study II) did not elicit a statistically significant rise neither of FENO nor of blood eosinophils between baseline and day 5. However, a subgroup of four individuals with a rise of blood eosinophils during nasal allergen provocations showed also a rise of FENO. CONCLUSIONS: We suppose that in allergic rhinitis a concomitant reaction of the bronchial system is dependent on a strong local inflammation leading to a generalized immune stimulation.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The diagnosis of an acute asthmatic attack in a child is made on a clinical basis. The severity of the exacerbation can be assessed by physical examination and measurement of the transcutaneous oxygenation saturation. A blood gas analysis can be helpful in this assessment. A child with a severe asthma exacerbation should be promptly referred to an emergency department of a hospital. Oxygen should be given to keep the oxygen saturation above 92% and short-acting, selective beta-2 agonists should be administered. Beta-2 agonists can be delivered by intermittent nebulization, continuous nebulization or by metered dose inhaler (MDI) with a spacer They can also be given intravenously in patients who are unresponsive to escalating therapy. The early administration of systemic corticosteroids is essential for the management of acute asthma in children. When tolerated, systemic corticoseroids can be given orally but inhaled corticosteroids are not recommended. Oxygen delivery, beta-2 agonists and steroid therapy are the mainstay of emergency treatment. Hypovolemia should be corrected either intravenously or orally. Administration of multiple doses of ipratropium bromide has been shown to decrease the hospitalization rate in children and adolescents with severe asthma. Clinical response to initial treatment is the main criterion for hospital admission. Patients with failure to respond to treatment should be transferred to an intensive care unit. A critical aspect of management of the acute asthma attack in a child is the prevention of similar attacks in the future.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

PURPOSE: We documented the effects of intradetrusor injections of botulinum neurotoxin type A (Botox(R)) for refractory idiopathic detrusor overactivity so that prospective patients maybe properly informed about possible improvement in quality of life, the duration of interinjection intervals and the risk of clean intermittent self-catheterization. MATERIALS AND METHODS: A total of 81 consecutive patients with refractory idiopathic detrusor overactivity treated with intradetrusor injections of 200 U botulinum neurotoxin type A at 20 sites per injection course were evaluated in this prospective, nonrandomized, open label cohort study. The primary outcome was changes in quality of life, as assessed by the short form of the Urogenital Distress Inventory and the Incontinence Impact Questionnaire before and after treatment. Secondary outcomes were the interinjection interval and the need for clean intermittent self-catheterization. RESULTS: After intradetrusor botulinum neurotoxin type A injections there was significant improvement in quality of life, which was sustained after repeat injections. Mean Urogenital Distress Inventory and Incontinence Impact Questionnaire scores decreased from 56 to 26 and 59 to 21 after injection 1 in 81 patients, from 52 to 30 and 51 to 24 after injection 2 in 24, from 40 to 19 and 43 to 17 after injection 3 in 13, from 44 to 17 and 61 to 15 after injection 4 in 6 and from 51 to 17 and 63 to 14 after injection 5 in 4, respectively. The median interinjection interval was 15, 12, 14 and 13 months between injections 1 and 2, 2 and 3, 3 and 4, and 4 and 5, respectively. Considering a post-void residual urine of greater than 100 ml with lower urinary tract symptoms as the indication for clean intermittent self-catheterization, the overall clean intermittent self-catheterization rate after treatment was 43%. CONCLUSIONS: Intradetrusor botulinum neurotoxin type A injections for refractory idiopathic detrusor overactivity significantly improved quality of life. This effect was sustained after repeat injection. More than 2 of 5 patients with refractory idiopathic detrusor overactivity required clean intermittent self-catheterization after botulinum neurotoxin type A injections and all prospective patients should be informed about this.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Postmenopausal bone loss can be prevented by continuous or intermittent estradiol (E2) administration. Concomitant progestogen therapy is mandatory in nonhysterectomized women to curtail the risk of endometrial hyperplasia or cancer. However, the recurrence of vaginal bleeding induced by sequential progestogen therapy in addition to continuous estrogen administration is one of the reasons for noncompliance to hormone replacement therapy (HRT). Tibolone, a synthetic steroid with simultaneous weak estrogenic, androgenic, and progestational activity, which does not stimulate endometrial proliferation, has recently been proposed for the treatment of climacteric symptoms. To compare the efficacy of conventional oral and transdermal HRT with that of tibolone in the prevention of postmenopausal bone loss, 140 postmenopausal women (age, 52 +/- 0.6 years; median duration of menopause, 3 years) were enrolled in an open 2-year study. Volunteers had been offered a choice between HRT and no therapy (control group, CO). Patients selecting HRT were randomly allocated to one of the following three treatment groups: TIB, tibolone, 2.5 mg/day continuously, orally; PO, peroral E2, 2 mg/day continuously, plus sequential oral dydrogesterone (DYD), 10 mg/day, for 14 days of a 28-day cycle; TTS, transdermal E2 by patch releasing 50 microg/day, plus DYD as above. Bone densitometry of the lumbar spine, upper femur, and whole body was performed using dual-energy X-ray absorptiometry at baseline, and then 6, 12, 18, and 24 months after initiation of therapy. One hundred and fifteen women (82%) completed the 2 years of the study. The dropout rate was similar in each group. Over 2 years, bone preservation was observed in all three treatment groups as compared with controls, without significant differences among treatment regimens. In conclusion, tibolone can be regarded as an alternative to conventional HRT to prevent postmenopausal bone loss.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Momentary brain electric field configurations are manifestations of momentary global functional states of the brain. Field configurations tend to persist over some time in the sub-second range (“microstates”) and concentrate within few classes of configurations. Accordingly, brain field data can be reduced efficiently into sequences of re-occurring classes of brain microstates, not overlapping in time. Different configurations must have been caused by different active neural ensembles, and thus different microstates assumedly implement different functions. The question arises whether the aberrant schizophrenic mentation is associated with specific changes in the repertory of microstates. Continuous sequences of brain electric field maps (multichannel EEG resting data) from 9 neuroleptic-naive, first-episode, acute schizophrenics and from 18 matched controls were analyzed. The map series were assigned to four individual microstate classes; these were tested for differences between groups. One microstate class displayed significantly different field configurations and shorter durations in patients than controls; degree of shortening correlated with severity of paranoid symptomatology. The three other microstate classes showed no group differences related to psychopathology. Schizophrenic thinking apparently is not a continuous bias in brain functions, but consists of intermittent occurrences of inappropriate brain microstates that open access to inadequate processing strategies and context information

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In young, first-episode, productive, medication-naive patients with schizophrenia, EEG microstates (building blocks of mentation) tend to be shortened. Koenig et al. [Koenig, T., Lehmann, D., Merlo, M., Kochi, K., Hell, D., Koukkou, M., 1999. A deviant EEG brain microstate in acute, neuroleptic-naïve schizophrenics at rest. European Archives of Psychiatry and Clinical Neuroscience 249, 205–211] suggested that shortening concerned specific microstate classes. Sequence rules (microstate concatenations, syntax) conceivably might also be affected. In 27 patients of the above type and 27 controls, from three centers, multichannel resting EEG was analyzed into microstates using k-means clustering of momentary potential topographies into four microstate classes (A–D). In patients, microstates were shortened in classes B and D (from 80 to 70 ms and from 94 to 82 ms, respectively), occurred more frequently in classes A and C, and covered more time in A and less in B. Topography differed only in class B where LORETA tomography predominantly showed stronger left and anterior activity in patients. Microstate concatenation (syntax) generally were disturbed in patients; specifically, the class sequence A→C→D→A predominated in controls, but was reversed in patients (A→D→C→A). In schizophrenia, information processing in certain classes of mental operations might deviate because of precocious termination. The intermittent occurrence might account for Bleuler's “double bookkeeping.” The disturbed microstate syntax opens a novel physiological comparison of mental operations between patients and controls.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

OBJECTIVE This study tested the hypotheses that intermittent coronary sinus occlusion (iCSO) reduces myocardial ischaemia, and that the amount of ischaemia reduction is related to coronary collateral function. DESIGN Prospective case-control study with intraindividual comparison of myocardial ischaemia during two 2-min coronary artery balloon occlusions with and without simultaneous iCSO by a balloon-tipped catheter. SETTING University Hospital. PATIENTS 35 patients with chronic stable coronary artery disease. INTERVENTION 2-min iCSO. MAIN OUTCOME MEASURES Myocardial ischaemia as assessed by intracoronary (i.c.) ECG ST shift at 2 min of coronary artery balloon occlusion. Collateral flow index (CFI) without iCSO, that is, the ratio between mean distal coronary occlusive (Poccl) and mean aortic pressure (Pao) both minus central venous pressure. RESULTS I.c. ECG ST segment shift (elevation in all) at the end of the procedure with iCSO versus without iCSO was 1.33±1.25 mV versus 1.85±1.45 mV, p<0.0001. Regression analysis showed that the degree of i.c. ECG ST shift reduction during iCSO was related to CFI, best fitting a Lorentzian function (r(2)=0.61). Ischaemia reduction with iCSO was greatest at a CFI of 0.05-0.20, whereas in the low and high CFI range the effect of iCSO was absent. CONCLUSIONS ICSO reduces myocardial ischaemia in patients with chronic coronary artery disease. Ischaemia reduction by iCSO depends on coronary collateral function. A minimal degree of collateral function is necessary to render iCSO effective. ICSO cannot manifest an effect when collateral function prevents ischaemia in the first place.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

After a short-term fever, complex regional pain syndrome, characterized by hyperalgesia, intermittent swelling, erythema and cyanosis of both feet, was diagnosed in a female veterinarian. The woman was infected with Bartonella koehlerae and she was also Bartonella vinsonii subsp. berkhoffii seroreactive. Having failed other treatments, symptoms resolved following initiation of antibiotics.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

BACKGROUND Congenital long-QT syndrome (LQTS) is potentially lethal secondary to malignant ventricular arrhythmias and is caused predominantly by mutations in genes that encode cardiac ion channels. Nearly 25% of patients remain without a genetic diagnosis, and genes that encode cardiac channel regulatory proteins represent attractive candidates. Voltage-gated sodium channels have a pore-forming alpha-subunit associated with 1 or more auxiliary beta-subunits. Four different beta-subunits have been described. All are detectable in cardiac tissue, but none have yet been linked to any heritable arrhythmia syndrome. METHODS AND RESULTS We present a case of a 21-month-old Mexican-mestizo female with intermittent 2:1 atrioventricular block and a corrected QT interval of 712 ms. Comprehensive open reading frame/splice mutational analysis of the 9 established LQTS-susceptibility genes proved negative, and complete mutational analysis of the 4 Na(vbeta)-subunits revealed a L179F (C535T) missense mutation in SCN4B that cosegregated properly throughout a 3-generation pedigree and was absent in 800 reference alleles. After this discovery, SCN4B was analyzed in 262 genotype-negative LQTS patients (96% white), but no further mutations were found. L179F was engineered by site-directed mutagenesis and heterologously expressed in HEK293 cells that contained the stably expressed SCN5A-encoded sodium channel alpha-subunit (hNa(V)1.5). Compared with the wild-type, L179F-beta4 caused an 8-fold (compared with SCN5A alone) and 3-fold (compared with SCN5A + WT-beta4) increase in late sodium current consistent with the molecular/electrophysiological phenotype previously shown for LQTS-associated mutations. CONCLUSIONS We provide the seminal report of SCN4B-encoded Na(vbeta)4 as a novel LQT3-susceptibility gene.