Associations between diet composition, dietary pattern, and weight outcomes after bariatric surgery: a systematic review.

INTRODUCTION: Literature describing the impact of dietary intake on weight outcomes after bariatric surgery has not been synthesized. This study aimed to synthesize the evidence regarding any association between diet composition and weight outcomes post-bariatric surgery. METHODS: CINAHL, Cochrane, Embase, MEDLINE and Scopus were searched for adult studies up to June 2021 that assessed any association between dietary intakes (≥1-macronutrient, food group, or dietary pattern) and weight outcomes at 12-months or longer after bariatric surgery. Risk of bias and quality assessments were conducted using the Scottish Intercollegiate Guidelines Network checklists and the NHMRC's Level of Evidence and Grades for Recommendations. Study findings were presented according to the time of post-surgery dietary intake assessment (≤12months, between 12 and 24 months, ≥24months). RESULTS: 5923 articles were identified, 260 were retrieved for full text screening, and 36 were eligible for inclusion (9 interventional including five randomized-controlled trials, and 27 observational cohort studies; sample sizes: 20-1610; total sample: 5065; follow-up periods: 1 year-12 years; level of evidence: II to IV, risk of bias: low to high). Findings on the association between long-term weight outcomes and dietary composition up to 24-months were mixed. After 24-months, studies consistently suggested no significant associations between weight loss and macronutrient composition or core food group patterns, or between carbohydrate, protein or food group patterns and weight recurrence. A single cohort study reported a weak association between diet quality score and weight-recurrence after 24-months. CONCLUSION: There was no strong evidence to support significant associations between diet composition and weight outcomes post-bariatric surgery. The heterogeneity in study design and quality may reduce generalizability to external populations. Individualized dietary recommendations may be useful to support long-term post-surgery weight outcomes. More studies are needed to define and measure diet quality in this patient cohort. REGISTRATION: PROSPERO (CRD42021264120).

SREBP maintains lipid biosynthesis and viability of cancer cells under lipid- and oxygen-deprived conditions and defines a gene signature associated with poor survival in glioblastoma multiforme.

Oxygen and nutrient limitation are common features of the tumor microenvironment and are associated with cancer progression and induction of metastasis. The inefficient vascularization of tumor tissue also limits the penetration of other serum-derived factors, such as lipids and lipoproteins, which can be rate limiting for cell proliferation and survival. Here we have investigated the effect of hypoxia and serum deprivation on sterol regulatory element-binding protein (SREBP) activity and the expression of lipid metabolism genes in human glioblastoma multiforme (GBM) cancer cells. We found that SREBP transcriptional activity was induced by serum depletion both in normoxic and hypoxic cells and that activation of SREBP was required to maintain the expression of fatty acid and cholesterol metabolism genes under hypoxic conditions. Moreover, expression of stearoyl-CoA desaturase, the enzyme required for the generation of mono-unsaturated fatty acids, and fatty acid-binding protein 7, a regulator of glioma stem cell function, was strongly dependent on SREBP function. Inhibition of SREBP function blocked lipid biosynthesis in hypoxic cancer cells and impaired cell survival under hypoxia and in a three-dimensional spheroid model. Finally, gene expression analysis revealed that SREBP defines a gene signature that is associated with poor survival in glioblastoma.

Whole-body vibration exposure in metropolitan bus drivers.

BACKGROUND: Back injuries are common in transit drivers, and can result in substantial direct and indirect cost to the employer and employee. Whole-body vibration (WBV) is one risk factor for drivers. Standards have been adopted (ISO 2631-1) to guide researchers in measuring and analysing WBV levels. Lately, a new standard has been added (ISO 2631-5) that takes impulsive exposures into account. AIMS: The aims of this study were to determine the levels of vibration for bus drivers using both ISO 2631-1 and 2631-5 standards, and whether there are differences in vibration levels and seat transmissibility between different road types. METHODS: Thirteen bus drivers drove a 7-year-old bus, instrumented to measure WBV in the seat and floor. The 52 km long test route included freeway, city streets and speed humps. Additionally, for comparison, a subset of five drivers also drove a car over the same route. RESULTS: Road type had a significant effect on all the vibration parameters. Based on exposure limit values in the standards, the continuous z-A (w)(8) exposures exceeded the limit value on freeways, and the impulsive z-VDV(8) and S (ed) exposures were above limit values in city streets and speed humps. Bus WBV exposures were about twice as high relative to the car and the bus seat amplified rather than attenuated WBV exposures. CONCLUSIONS: Bus drivers are potentially being exposed to daily vibration levels higher than recommended especially on certain road types. The current seat in this study does not attenuate the vibration.

Diagnostic yield of bronchoscopic sampling in febrile neutropenic patients with pulmonary infiltrate and haematological disorders.

BACKGROUND: The development of pulmonary infiltrate in neutropenic patients is potentially life-threatening, and requires early diagnosis and treatment. Bronchoscopic sampling is an established form of investigation in such patients. AIM: The aim of the study is to determine the diagnostic yield and complication rate of bronchoscopic sampling in patients with a haematological disorder presenting with febrile neutropenia and pulmonary infiltrate. METHODS: Medical records and laboratory investigations were retrospectively reviewed for all patients with a haematological disorder who underwent flexible bronchoscopy and bronchoalveolar lavage (BAL) or bronchial washing (BW) at Auckland City Hospital, New Zealand, after presenting with febrile neutropenia and pulmonary infiltrate between January 2008 and December 2009. Demographic, clinical, radiological and microbiological data, procedure-related complications and treatment were recorded. Modifications to treatment regimens as a result of bronchoscopy and 30-day mortality were recorded. RESULTS: Out of 678 bronchoscopies performed during this period, 26 were in patients with a haematological disorder presenting with febrile neutropenia and pulmonary infiltrate. Most patients had a haematological malignancy (19/26). Two (7.7%) patients reported minor haemoptysis. No biopsies were performed. Positive microbiological samples were obtained with BAL/BW in 23% of patients. The most common organisms identified were Aspergillus species (15.4%); other organisms were Candida (11.6%) and Streptococcus pneumoniae (3.9%). The bronchoscopic results altered the clinical management of 10 (38.4%) patients. The 30-day mortality rate was 19.2%, but no deaths were related to the procedure. CONCLUSIONS: In haematology patients presenting with febrile neutropenia and pulmonary infiltrate, bronchoscopy is a safe procedure that plays a significant role in management.

Clinical failures associated with rpoB mutations in phenotypically occult multidrug-resistant Mycobacterium tuberculosis.

SETTING: Recently, Mycobacterium tuberculosis isolates have been described that test phenotypically susceptible to rifampicin (RMP) yet harbour genotypic rpoB mutations. OBJECTIVE: 1) To investigate the impact of such mutations on clinical outcomes among RMP-susceptible isolates, and 2) to determine the prevalence of rpoB mutations among isoniazid (INH) monoresistant isolates at our laboratory and to describe the association between the presence of these mutations and clinical outcomes. METHODS: M. tuberculosis isolates were screened for mutations in the rpoB gene using the Cepheid Gene-Xpert® MTB/RIF assay. Clinical correlation was made by reviewing patient case notes. RESULTS: Isolates from 94 patients were found to have INH-resistant, RMP-susceptible profiles. Clinical information was available for 52 patients, including three whose isolates had rpoB mutations. All three of these patients had treatment failures, compared to two of 49 patients whose isolates did not have rpoB mutations (P = 0.0005). DISCUSSION: We demonstrate a significant association between the presence of rpoB gene mutations that are not detected at the current RMP critical concentration and treatment failure. We suggest that a review of the current RMP critical concentration is warranted to ensure that RMP is not used inappropriately for the treatment of phenotypically occult multidrug-resistant tuberculosis.

Isolated nocturnal desaturation in COPD: prevalence and impact on quality of life and sleep.

BACKGROUND AND AIMS: The clinical impact of nocturnal desaturation on health related quality of life (HRQL) and sleep in chronic obstructive pulmonary disease (COPD) has been little studied. The aim of this study was to evaluate the prevalence and clinical impact of nocturnal desaturation in a typical outpatient population with COPD. PATIENTS AND METHODS: Between 2002 and 2005, consecutive patients with COPD attending outpatient services at the study centre underwent resting oximetry if they were not on domiciliary oxygen therapy. If their resting saturations were less than 95%, overnight pulse oximetry was performed. Significant nocturnal desaturation was defined as spending more than 30% of at least one of two nights with a saturation of less than 90%. The Chronic Respiratory Questionnaire (CRQ) and Short Form 36 (SF36) were used to assess HRQL, and the Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Score (ESS) and Functional Outcomes of Sleep (FOSQ) questionnaires were used to assess sleep quality and daytime function. RESULTS: Of 1104 patients, 803 underwent resting oximetry and 79 had resting oxygen saturations of less than 95%. Of these, 59 agreed to undergo overnight oximetry (mean age 70 years, forced expiratory volume in 1 s 37.2% predicted, resting Po(2) on air 8.9 kPa). Significant nocturnal desaturation was seen in 29 (49.2%) of the 59 subjects. Assuming the less hypoxic patients do not have nocturnal desaturation, the prevalence of nocturnal desaturation in the whole clinic population could be estimated at 4.8%. There were no significant differences in CRQ, SF36, PSQI, ESS or FOSQ scores for desaturators compared with non-desaturators. CONCLUSION: Significant nocturnal desaturation was common in patients with COPD with resting saturations of less than 95%, but was estimated to have a prevalence of less than 5% in the whole outpatient population. Nocturnal desaturation was not associated with impairment of HRQL, sleep quality or daytime function.

Animal models of cough: literature review and presentation of a novel cigarette smoke-enhanced cough model in the guinea-pig.

A wealth of literature describes the approaches that investigators have used to develop animal models of cough. The relevance of the models to cough in man and disease is still unknown. Furthermore, the choice of animal model that is used will depend on the purpose of the investigation and what questions are being asked. Cigarette smoke is known to cause COPD and cough is a principle symptom where patients demonstrate an increased cough response to citric acid or capsaicin. This paper describes the development of exacerbated cough to these agents in the guinea-pig following cigarette smoke exposure and pharmacological profiling of these models. Male Dunkin-Hartley guinea-pigs were exposed to air or cigarette smoke (4 or 5 research cigarettes daily for the capsaicin and citric acid studies, respectively) for a 3 s puff every 30 s, for up to 10 days. At selected time points conscious, unrestrained animals were placed in a plethysmograph chamber and challenged with an aerosol of 0.3 M citric acid (10 min) or 10 microM capsaicin (7 min). Cough and Penh area under the curve (AUC) were recorded during the exposure and for a further 10 min (citric acid) or 8 min (capsaicin) after exposure. Compounds were administered on day 3 or 11 for citric acid or capsaicin, respectively. Significant enhancement of citric acid-induced cough was evident 24 h (12+/-2 to 24+/-4* coughs) after a single exposure and further enhanced after 2 days (13+/-3 to 36+/-4* coughs). Enhanced cough to capsaicin was not reliable until after 10 days of cigarette smoke exposure (2+/-1 to 14+/-3** coughs). Data are expressed as mean+/-s.e.mean (n=10), *p<0.05, **p<0.01 vs. air-exposed animals (Mann-Whitney rank-sum test). The minimum effective doses to inhibit citric acid-induced cough were 10, 10, 3 and 0.3 mg/kg for codeine (p.o. -30 min), a selective NK(1)/NK(2) antagonist, DNK333 (p.o. -2 h), terbutaline (s.c. -1 h) and atropine (s.c. -1 h), respectively. The minimum effective doses to inhibit capsaicin-induced cough were 3, 1, 0.3 and 0.3 mg/kg for codeine, DNK333, terbutaline (p.o. -2 h) and atropine, respectively. The VR1 antagonists capsazepine and iodo-resiniferatoxin (IRTX) did not inhibit cough in either model. Differences in sensitivity between citric acid and capsaicin to pharmacological agents may be partly explained by the difference in magnitude of response to these agents. Clinically used compounds such as codeine and terbutaline have shown activity in both models, however the relevance of the models to cough in man and disease for potential new therapies is unknown.

Short-burst oxygen therapy for COPD patients: a 6-month randomised, controlled study.

Short-burst oxygen therapy (SBOT) remains widely advocated for patients with chronic obstructive pulmonary disease (COPD), despite a lack of supporting evidence. The aim of this randomised, double-blind, placebo-controlled, parallel group study was to determine whether SBOT improves health-related quality of life (HRQL) or reduces acute healthcare utilisation in patients discharged following an acute exacerbation of COPD. Consecutive patients were screened; 78 of 331 were eligible for randomisation to cylinder oxygen, cylinder air or usual care following discharge. Patients were elderly with high acute healthcare utilisation, forced expiratory volume in one second of <1 L and had dyspnoea limiting daily activity but were not hypoxaemic at rest. Over the 6-month study period, there were no significant differences between patient groups in HRQL (Chronic Respiratory Questionnaire (CRQ), 36-item Short-Form Health Survey, Hospital Anxiety and Depression Scale) except for CRQ emotion domain. There were no significant differences in acute healthcare utilisation. Time to readmission was greatest in the usual care group. Cylinder use was high initially, but rapidly fell to very low levels within weeks in both cylinder oxygen and air groups. In conclusion, the availability of short-burst oxygen therapy for chronic obstructive pulmonary disease patients discharged from hospital following an acute exacerbation did not improve health-related quality of life or reduce acute healthcare utilisation. These results provide no support for the widespread use of short-burst oxygen therapy.

Development of educational image databases and e-books for medical physics training.

Medical physics education and training requires the use of extensive imaging material and specific explanations. These requirements provide an excellent background for application of e-Learning. The EU projects Consortia EMERALD and EMIT developed five volumes of such materials, now used in 65 countries. EMERALD developed e-Learning materials in three areas of medical physics (X-ray diagnostic radiology, nuclear medicine and radiotherapy). EMIT developed e-Learning materials in two further areas: ultrasound and magnetic resonance imaging. This paper describes the development of these e-Learning materials (consisting of e-books and educational image databases). The e-books include tasks helping studying of various equipment and methods. The text of these PDF e-books is hyperlinked with respective images. The e-books are used through the readers' own Internet browser. Each Image Database (IDB) includes a browser, which displays hundreds of images of equipment, block diagrams and graphs, image quality examples, artefacts, etc. Both the e-books and IDB are engraved on five separate CD-ROMs. Demo of these materials can be taken from www.emerald2.net.

Chest radiography: a comparison of image quality and effective dose using four digital systems.

Image quality (IQ) and effective dose for chest radiography was compared for four digital imaging systems that used three different detector technologies: a-Si/TFT flat-panel detector (FPD), scanning-slot/charge-coupled device (CCD) and photostimuable phosphor (PSP). On each system a phantom was exposed at 125 kV(p) for automatic exposure control (AEC) and 2, 4 and 8 Gy receptor dose using identical geometrical conditions. All images were scored as softcopy images by three observers. The effective dose was calculated for each exposure condition. For AEC, superior IQ was observed for the GE FPD compared with all the other systems, which showed similar IQ performance. For all systems the entrance surface dose associated with AEC was within the European recommendations but variations in the effective dose were observed between the four systems. For identical receptor dose levels superior IQ was observed with the FPDs. Thorascan was noted for its low effective dose and Agfa CR was associated with the highest effective dose. FPD systems showed a better overall performance, followed by the CCD and PSP systems.

Short-burst oxygen immediately before and after exercise is ineffective in nonhypoxic COPD patients.

Short-burst oxygen therapy (SBOT) remains an unproven treatment for reduction of exertional dyspnoea in chronic obstructive pulmonary disease (COPD). This study aimed to assess whether SBOT before exercise reduces dyspnoea or improves performance, and whether SBOT after exercise reduces dyspnoea during recovery. Twenty-two clinically stable COPD patients (mean forced expiratory volume in one second 34% predicted, mean resting saturation 94%) attended a respiratory gymnasium and undertook four 6-min walk (6MW) tests at each of two sessions, 1 week apart. Cylinder air or oxygen was administered single-blind in random order for 5 min prior to the first two 6MW and during recovery following the final two 6MW. Dyspnoea was self-rated by subjects using the modified Borg scale. There was no significant difference in mean 6MW distance or final Borg score for air and oxygen given before exercise. There was also no significant difference in mean time-to-resting Borg score for air and oxygen given after exercise. Only two subjects demonstrated a clinically significant and consistent reduction in dyspnoea for oxygen compared with air either before or after exercise. Overall, short-burst oxygen therapy neither reduced dyspnoea nor improved performance. This study does not support the use of short-burst oxygen therapy either immediately before or after exercise.

Cultural stereotype of the effects of religion on mental health.

To examine if the religious are more likely to be rated as having a poorer mental health than the non-religious, 48 Northern Irish undergraduate students completed self-report measures of religious attitude and mental health under four counter-balanced conditions: 'control' (present yourself 'as you really are') and as how 'religious', 'nonreligious', and 'mentally ill' respondents might be thought to answer. The 'religious' condition provided significantly higher scores for both the Obsessional Symptom Scale and the Obsessional Personality Trait Scale and significantly lower Psychoticism Scale scores than the 'non-religious' condition. Moreover, significant associations were found between higher scores on the religiosity scale and higher scores on the Obsessional Personality Trait Scale in two of the four conditions ('religious' and 'mentally ill') and lower scores on the Psychoticism Scale in three of the four conditions ('control', 'religious', and 'mentally ill'). These results suggest that the religious are viewed paradoxically as having both aspects of better (i.e. lower psychoticism scores) and poorer mental health (i.e. higher obsessional scores) than the non-religious. As such, the present findings provide some support for the existence of a powerful cultural stereotype of the religious.

Ca(2+)/calmodulin-dependent protein kinase mediates the phosphorylation of CD44 required for cell migration on hyaluronan.

CD44 is the principal cell surface receptor for the extracellular matrix glycosaminoglycan hyaluronan, and binding to this ligand underlies CD44-mediated cell attachment and migration. As would be expected for a widely expressed adhesion receptor, CD44 is subject to complex regulatory events, and mis-regulation of the receptor has been associated with a number of disease pathologies, including chronic inflammatory conditions and the progression of metastatic tumours. In previous studies we have demonstrated that a key control point for this receptor is the phosphorylation of CD44 on a conserved cytoplasmic serine residue, Ser(325). This modification is not required for efficient ligand binding, but is an essential component of CD44-dependent cell migration on a hyaluronan substratum. To understand better the mechanism regulating CD44 phosphorylation on Ser(325), we have generated a monoclonal antibody that specifically recognizes CD44 phosphorylated on Ser(325), and have developed assays to identify the Ser(325) kinase. We demonstrate here that CD44 is phosphorylated to high stoichiometry in resting cells and that Ca(2+)/calmodulin-dependent protein kinase II is a CD44 Ser(325) kinase.

Convergent validity of the Depression-Happiness Scale with the Memorial University of Newfoundland Scale of Happiness.

The Depression-Happiness Scale and the Memorial University of Newfoundland Scale of Happiness were administered to 52 Northern Irish university students. Higher scores on the Depression-Happiness Scale were significantly associated with higher scores on the Memorial University of Newfoundland Scale and the subscale scores of Positive Affect and Positive Experiences and with lower scores on Negative Affect and Negative Experiences. These data provide further support for the convergent validity of the Depression-Happiness Scale.