The impact of a 4-hour sleep delay on slow wave activity in twins discordant for chronic fatigue syndrome

OBJECTIVES: Chronic fatigue syndrome (CFS) has been associated with altered amounts of slow wave sleep, which could reflect reduced delta electroencephalograph (EEG) activity and impaired sleep regulation. To evaluate this hypothesis, we examined the response to a sleep regulatory challenge in CFS. DESIGN: The first of 3 consecutive nights of study served as laboratory adaptation. Baseline sleep was assessed on the second night. On the third night, bedtime was delayed by 4 hours, followed by recovery sleep. Total available sleep time was held constant on all nights. SETTING: A research sleep laboratory. PARTICIPANTS: 13 pairs of monozygotic twins discordant for CFS. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: Power spectral analysis quantified slow wave activity (SWA) in the 0.5-3.9 Hz band in successive NREM periods (stage 2, 3, or 4) on each night. To ensure comparability, analyses were restricted to the first 4 NREM periods on each night. Data were coded for NREM period and twin pair. Repeated-measures analysis of variance (ANOVA) contrasted sleep delay effects across NREM periods between twin pairs. A second ANOVA calculated the SWA in each NREM period in recovery sleep relative to baseline SWA. The 2 groups of twins were similar on baseline SWA power. After sleep delay, CFS twins exhibited significantly less SWA power in the first NREM period of recovery sleep and accumulated a smaller percentage of SWA in the first NREM period than their co-twins. CONCLUSIONS: CFS is associated with a blunted SWA response to sleep challenge, suggesting that the basic sleep drive and homeostatic response are impaired.     

Additional luminal area gain by intravascular ultrasound guidance after coronary stent implantation with high inflation pressure

Aims: Studies by intravascular ultrasound demonstrated inadequate expansion in a large number of stents, which lead to the increase of inflation pressures for stenting. The present study examined whether routine use of high-pressure inflation would be sufficient for an optimum stent expansion without sonographic guidance. Methods and results: Two types of single coronary stents (Palmaz-Schatz in 54, and Wiktor in 25) were implanted with inflation pressures of 16–20 atm in 79 nonocclusive coronary lesions. IVUS before stenting was used in 78% to select the adequate stent size. Intravascular ultrasound after stenting was used to assess the minimum stent area and diameter, the reference areas, and the strut apposition to the vessel wall. The difference between the area of the expanding balloon and the stent area was calculated as the luminal deficit of the stent. Completeness of stent expansion required full strut apposition and lesion coverage, and a minimum stent area that was larger than the distal reference, and larger than 60% of the proximal reference. Intravascular ultrasound before stenting lead to an increase of the stent size in 47%. After high-pressure expansion, even with the optimized balloon size, 8% of stents had struts protruding into the lumen. The stent area (6.87 ± 1.93 mm²) was significantly smaller than both the proximal (9.59 ± 2.91 mm²; p<0.001) and distal reference area (8.23 ± 3.03 mm²; p<0.001). The criteria for complete expansion were met in 48%. The expansion with a larger high-pressure balloon in 28 stents lead to an increase of the stent area by 19% (8.19 ± 2.24; p<0.001), and full stent apposition in all cases. The criteria of stent expansion were met in 82%. A wide range of the luminal deficit upto 48% was observed, which was not related to sonographic lesion characteristics, except in lesions with complete circumferential calcifications. The different stent designs were characterized by a slightly lower luminal deficit in slotted-tube stents (23 ± 13% vs. 28 ± 12%; p=0.11) and a better index of stent symmetry as compared with the coil stent (0.87 ± 0.08 vs. 0.82 ± 0.09; p<0.05). Conclusion: Routine use of high-pressure stent expansion did not lead to a sufficient stent expansion, even when the initial stent size had been guided by intravascular ultrasound. Further stent dilatation with larger balloons under ultrasound guidance would be required to optimize the luminal area gain.     

High nodal FDG uptake increases risk of distant metastasis in patients with oropharyngeal squamous cell carcinoma

European Journal of Nuclear Medicine and Molecular Imaging - The purpose of this study was to investigate if FDG uptake metrics in primary tumor and lymph node metastases in patients with...     

Gastric band is safe and effective at three years in a national study subgroup of non-morbidly obese patients

Aim

To analyze the 3-year outcomes of lower body mass index (BMI) (<35 kg/m²) adjustable gastric band (AGB) recipients across multiple sites in the French health insurance system.

Methods

From prospectively collected data on a cohort of 517 morbidly obese Swedish Adjustable Gastric Band^® (SAGB) patients (Clinical Trials Web database, #{"type":"clinical-trial","attrs":{"text":"NCT01183975","term_id":"NCT01183975"}}NCT01183975), a retrospective analysis of a subgroup of 29 low-BMI patients was conducted. Patients had a severe obesity-related comorbidity, had undergone a prior bariatric procedure requiring reintervention, or had a maximum adult BMI≥40. Safety (mortality, adverse events) and effectiveness (BMI change, excess weight loss [EWL, %], total body weight loss [%TBWL], quality of life [QoL], and comorbidities) were evaluated.

Results

Multiple surgical teams/sites enrolled patients and performed SAGB procedures between September 2, 2007 and April 30, 2008. Of 29 low-BMI patients (mean age, 41.3 ± 10.3 years), 89.7% were female, and obesity duration was 13.6 ± 7.3 years. Mean BMI was 31.5 ± 3.7; there were 37 comorbidities in 15/29 patients. At 3-year follow-up, BMI was 29.4 ± 4.9 (mean change, -2.3 ± 6.2; P = 0.069); total cohort EWL, 7.3 ± 74.8%; TBWL, 6.2 ± 18.8%; BMI≥30 to <35 EWL, 38.8 ± 48.0%; there were 7 comorbidities in 15/29 patients (P < 0.031). There were 20 adverse events in 13 patients (44.8%); SAGBs were retained in 25/29 (86.2%) at 3 years.

Conclusions

In a retrospective analysis of a subgroup of BMI<35 kg/m² patients, some following a prior bariatric procedure, SAGB was found to be safe and effective at 3-year follow-up.For over 2 decades, since publication of the 1991 National Institutes of Health (NIH) consensus conference statement (1), the cutoff point for bariatric surgery has been morbid obesity (body mass index [BMI, kg/m²]≥40 or ≥35 with comorbidities), also termed class II obesity by the World Health Organization (WHO) (2). This demarcation of access to bariatric surgery was based on the observation that an increase in BMI leads to an increase in the risk of comorbid illness and premature death. Yet, investigation of the potential value of bariatric surgery as a safe and effective treatment for overweight (BMI 25-<30) and obesity class I (BMI≥30 to <35) patients has been under way since the publication of the NIH statement. In 1992 and 1995 landmark studies (3,4), Pories et al theorized that bariatric procedures might be safe and as beneficial for weight loss and comorbidity reduction in non-morbidly obese patients as it was in the morbidly obese (5). In the last half decade, the least-invasive, lowest-risk restrictive procedures, such as adjustable gastric banding (AGB), have been employed at the forefront of exploring surgical options for the <35 BMI patient.Adjustable gastric banding comprised the vast majority, nearly 90%, of bariatric procedures performed in morbidly obese patients in France prior to 2008 (6). To assess the national social insurance-supported use of the Swedish Adjustable Gastric Band (SAGB) (7,8), the French government commissioned a prospective, 31-center, “real-life,” observation of SAGB safety and effectiveness in class II and III obese patients (9). Between September 2, 2007 and April 30, 2008, patients were selected and underwent SAGB implantation in rural and urban centers. SAGB weight-loss effectiveness analyzed on an intent-to-treat basis at the 3-year study endpoint was comparable to that of AGB findings summarized by global meta-analyses (10,11). Under the “real-world” SAGB study protocol requirement of consecutive recruitment and surgeon discretion, 29 patients (5.6% of 517) were included in the national SAGB study who presented with a BMI<35 and a severe obesity-related comorbidity, and/or had experienced a prior complicated bariatric surgery requiring revision, and/or had previously sustained a maximum adult BMI≥40. With the aim of contributing safety and effectiveness findings to the growing <35 BMI evidence base, we report 3-year outcomes for the French low-BMI SAGB study group.     

Predictors of total and low-density lipoprotein cholesterol change after partial ileal bypass

POSCH is a prospective, randomized secondary intervention trial examining the effect of maximal lipoprotein modification achieved by partial ileal bypass on overall mortality and the course of coronary heart disease. In the initial 189 surgical patients, total cholesterol levels decreased from 256.7 +/- 2.6 mg/dl to 166.6 +/- 2 mg/dl, and low-density lipoprotein cholesterol levels decreased from 181.5 +/- 2.7 mg/dl to 94.1 +/- 1.7 mg/dl 3 months after operation. These significant decreases were sustained through 5 years of follow-up (p less than 0.001). The total cholesterol level was 29.2 +/- 0.9 percent lower and the low-density lipoprotein cholesterol level was 43.2 +/- 1 percent lower at 5 years compared with the baseline level. Decreases of similar magnitude were seen in each of the common WHO lipoprotein phenotypes. The baseline total cholesterol level was the only significant independent preoperative predictor of the 5 year total cholesterol level (correlation coefficient 0.547; p less than 0.001), and the baseline low-density lipoprotein cholesterol level was the only significant independent preoperative determinant of the 5 year low-density lipoprotein cholesterol level (correlation coefficient 0.599; p less than 0.001). These relationships are expressed by the following equations: 5 year total cholesterol = 0.54 X baseline total cholesterol + 42.3, and 5 year low-density lipoprotein cholesterol = 0.455 X baseline low-density lipoprotein cholesterol + 19.2. The decrease in total and low-density lipoprotein cholesterol levels after partial ileal bypass are greater than reported by any trial of drug or diet intervention, including the Lipid Research Clinics Coronary Primary Prevention Trial which examined cholestyramine. Estimation of the change in total and low-density lipoprotein cholesterol levels after partial ileal bypass can be made based on preoperative lipid analysis and is essential in comparing different therapeutic modalities and assessing the role of partial ileal bypass among strategies aimed at lowering coronary heart disease risk.     

Pilot study of oxygen transport rate of banked red blood cells

Background and Objectives  Dynamic oximetry provides a new way to assess the effect of blood storage on the oxygen transport rate (OTR).
Materials and Methods  In dynamic oximetry, the rate at which oxyhemoglobin becomes deoxyhemoglobin is measured optically, thereby, indirectly measuring the rate at which oxygen leaves the red blood cell (RBC) making it available for transfer to tissues. Extending the physiologic diffusion time in an in vitro apparatus, consisting of a diffusion system and gas exchanger capable of controlling the surface area and the time of exposure for oxygenation and deoxygenation, makes OTR measurement feasible. Eight normal blood donor units, collected in adenine, dextrose, sorbitol, sodium chloride and mannitol , were stored for 8 weeks under standard conditions and serially sampled for OTR.
Results  We report that the OTR at the time of blood bank donation appears to be singular for each donor, that the interdonor differences are maintained over time, and that the individual OTR increased 1·72-fold (95% CI 1·51, 1·95) over 8 weeks, adjusting for sex, age and plasma cholesterol level.
Conclusion  Oxygen transport rate increases during storage; blood units with similar haemoglobin content may have significant differences in OTR. Studies examining blood parameters at the time of donation and blood storage on patient outcomes should consider measuring OTR, as it may contribute to differences in observed efficacy of tissue oxygenation.