Investigating the relationship between substance use and sexual behaviour in young people in Britain: findings from a national probability survey

BACKGROUND

Health risk behaviours are prominent in late adolescence and young adulthood, yet UK population-level research examining the relationship between drug or alcohol use and sexual health and behaviour among young people is scarce, despite public health calls for an integrated approach to health improvement. Our objective was to further our understanding of the scale of and nature of any such relationship, using contemporary data from Britain's third National Survey of Sexual Attitudes and Lifestyles (Natsal-3).

METHODS

Analyses of data from Natsal-3, a stratified probability survey of 15 162 men and women (3869 aged 16-24 years), undertaken in 2010-2012, using computer-assisted personal interviewing, were carried out. Logistic regression was used to explore associations between reporting (1) frequent binge drinking (≥weekly), (2) recent drug use (within past 4 weeks) or (3) multiple (both types of) substance use, and key sexual risk behaviours and adverse sexual health outcomes. We then examined the sociodemographic profile, health behaviours and attitudes reported by 'risky' young people, defined as those reporting ≥1 type of substance use plus non-condom use at first sex with ≥1 new partner(s), last year.

RESULTS

Men and women reporting frequent binge drinking or recent drug use were more likely to report: unprotected first sex with ≥1 new partner(s), last year; first sex with their last partner after only recently meeting; emergency contraception use (last year) and sexually transmitted infection diagnosis/es (past 5 years). Associations with sexual risk were frequently stronger for those reporting multiple substance use, particularly among men. The profile of 'risky' young people differed from that of other 16-24 years old.

CONCLUSIONS

In this nationally representative study, substance use was strongly associated with sexual risk and adverse sexual health outcomes among young people. Qualitative or event-level research is needed to examine the context and motivations behind these associations to inform joined-up interventions to address these inter-related behaviours.

Insulin signaling, inflammation, and lipolysis in subcutaneous adipose tissue of transition dairy cows either overfed energy during the prepartum period or fed a controlled-energy diet

Adipose tissue mobilization is a hallmark of the transition period in dairy cows. Cows overfed energy during the dry period have higher concentrations of nonesterified fatty acids (NEFA) and β-hydroxybutyrate (BHB) compared with cows fed a controlled-energy diet prepartum. The reason for an increase in blood NEFA concentrations at the level of adipose tissue in cows overfed energy has not been fully elucidated. One hypothesis is that cows with high BHB concentrations suffer from adipose tissue-specific insulin resistance, leading to higher rates of adipose tissue mobilization in the postpartum period. To test this hypothesis, subcutaneous adipose tissue biopsies of cows overfed energy in excess of predicted requirements by 50% in the dry period, and that had high concentrations of blood BHB postpartum (group H; n=12), were used. Findings were compared with results of biopsies from cows fed a controlled-energy diet and with low BHB concentrations postpartum (group C; n=12) to create the biggest contrast in BHB concentrations. Subcutaneous adipose tissue biopsies were obtained before and 60 min after an intravenous glucose challenge (0.25 g/kg of glucose) at 28 and 10 d before expected calving as well as on d 4 and 21 postpartum. Phosphorylation of protein kinase B, extracellular signal-regulated kinase, and hormone-sensitive lipase was determined before and after glucose infusion by Western blot. Western blot was also used to assess the baseline protein abundance of peroxisome proliferator-activated receptor gamma and insulin receptor β-subunit. In addition, gene expression of fatty acid synthase, adiponectin, monocyte chemoattractant protein 1, and tumor necrosis factor α was determined by real-time quantitative reverse-transcription PCR. Backfat thickness was determined in the thurl area by ultrasonography. Cows in group H showed a greater degree of lipogenesis prepartum, but no differences were found in lipolytic enzyme activity postpartum compared with cows in group C. Baseline plasma insulin concentrations were decreased and serum NEFA concentrations increased postpartum in group H. Insulin signaling through protein kinase B, quantity of insulin receptor, markers of inflammation, and peroxisome proliferator-activated receptor gamma in adipose tissue were not different between the groups, but expression of adiponectin was increased in adipose tissue of cows in group H during the immediate peripartum period. In conclusion, differences in serum concentrations of NEFA between cows overfed energy prepartum and high blood concentrations of BHB are likely due to greater negative energy balance postpartum reflected in lower circulating concentrations of glucose and insulin and an increase in the total amount of mobilized adipose tissue mass rather than due to changes in adipose tissue insulin signaling.

Short communication: Association of milk fatty acids with early lactation hyperketonemia and elevated concentration of nonesterified fatty acids

The objective of our study was to extend the limited research available on the association between concentrations of milk fatty acids and elevated nonesterified fatty acids (NEFA) and β-hydroxybutyrate (BHB) concentrations in early lactation dairy cattle. Measurement of milk fatty acids for detection of cows in excessive negative energy balance has the potential to be incorporated in routine in-line monitoring systems. Blood samples were taken from 84 cows in second or greater lactation 3 times per week between 3 to 14 d in milk. Cows were characterized as hyperketonemic (HYK) if blood BHB concentration was ≥1.2mmol/L at least once and characterized as having elevated concentrations of NEFA (NEFAH) if serum NEFA concentration was ≥1mmol/L at least once. Composition of colostrum and milk fatty acids at wk 2 postpartum was used to investigate the potential diagnostic value of individual fatty acids and fatty acid ratios for the correct classification of cows with NEFA and BHB concentrations above these thresholds, respectively. Receiver operating characteristic (ROC) curves were used to identify thresholds of fatty acid concentration and fatty acid ratios when ROC area under the curve was ≥0.70. Correct classification rate (CCR, %) was calculated as {[(number of true positives + number of true negatives)/total number tested] × 100}. None of the colostrum fatty acids yielded a sufficiently high area under the curve in ROC analysis for the association with HYK and NEFAH. The following fatty acids and fatty acid ratios were identified for an association with NEFAH (threshold, CCR): C15:0 (≤0.65g/100g, 68.3%); cis-9 C16:1 (≥1.85g/100g, 70.7%); cis-9 C18:1 (≥26g/100g, 69.5%), cis-9 C18:1 to C15:0 ratio (≥45, 69.5%); cis-9 C16:1 to C15:0 (≥2.50, 73.2%). Several fatty acids were associated with HYK (threshold, CCR): C6:0 (≤1.68g/100g, 80.5%), C8:0 (≤0.80g/100g, 80.5%), C10:0 (≤1.6g/100g, 79.3%); C12:0 (≤1.42g/100g, 82.9%); C14:0 (≤6.10g/100g, 84.1%); C15:0 (≤0.50g/100g, 82.9%), cis-9 C18:1 (≥30g/100g, 81.7%). The use of fatty acid ratios did not improve CCR over using individual fatty acids for the classification of HYK. Colostrum fatty acid composition was not useful in predicting NEFAH or HYK between 3 to 14 d in milk. Accuracy of milk fatty acids and fatty acid ratios to correctly classify cows with elevated concentrations of NEFA and BHB between 3 to 14 d in milk was moderate and overall higher for HYK. Determining changes in the fatty acid composition of milk fat from milk samples at wk 2 postpartum for the detection of cows with elevated concentrations of BHB and NEFA can currently not be recommended to replace direct measurement. Future applications should target repeated milk sampling between 3 to 14 d in milk to identify the best sampling for determination of milk fatty acid composition within the first 2 wk postpartum.

Relapse after withdrawal from anti-TNF therapy for inflammatory bowel disease: an observational study, plus systematic review and meta-analysis

BACKGROUND

Infliximab and adalimumab have established roles in inflammatory bowel disease (IBD) therapy. UK regulators mandate reassessment after 12 months' anti-TNF therapy for IBD, with consideration of treatment withdrawal. There is a need for more data to establish the relapse rates following treatment cessation.

AIM

To establish outcomes following anti-TNF withdrawal for sustained remission using new data from a large UK cohort, and assimilation of all available literature for systematic review and meta-analysis.

METHODS

A retrospective observational study was performed on 166 patients with IBD (146 with Crohn's disease (CD) and 20 with ulcerative colitis [UC) and IBD unclassified (IBDU)] withdrawn from anti-TNF for sustained remission. Meta-analysis was undertaken of all published studies incorporating 11 further cohorts totalling 746 patients (624 CD, 122 UC).

RESULTS

Relapse rates in the UK cohort were 36% by 1 year and 56% by 2 years for CD, and 42% by 1 year and 47% by 2 years for UC/IBDU. Increased relapse risk in CD was associated with age at diagnosis [hazard ratio (HR) 2.78 for age <22 years], white cell count (HR 3.22 for >5.25 × 10⁹ /L) and faecal calprotectin (HR 2.95 for >50 μg/g) at drug withdrawal. Neither continued immunomodulators nor endoscopic remission were predictors. In the meta-analysis, estimated 1-year relapse rates were 39% and 35% for CD and UC/IBDU respectively. Retreatment with anti-TNF was successful in 88% for CD and 76% UC/IBDU.

CONCLUSIONS

Assimilation of all available data reveals remarkable homogeneity. Approximately one-third of patients with IBD flare within 12 months of withdrawal of anti-TNF therapy for sustained remission.

Fetuin-A and vascular calcification in Indian end-stage renal disease population

Fetuin-A levels, its correlation with vascular calcification and other biochemical markers of chronic kidney disease-mineral and bone disorder (CKD-MBD) has not been studied in Indian end-stage renal disease population. Forty patients on dialysis for more than 3 months were studied. Biochemical parameters of CKD-MBD, highly sensitive-C reactive protein (hs-CRP), lipid profile and fetuin-A levels were estimated. Multi-slice computed tomography (MSCT) at the level of L1-L4 was done, and calcification score calculated using AJ 130 smart score. Levels of fetuin-A were correlated with calcification score and biochemical markers of CKD-MBD. Mean fetuin-A levels were 0.33 ± 0.098 g/l. Positive correlation of abdominal aortic calcification scores was found with age (P < 0.01) and duration of dialysis (P = 0.018). No correlation was detected between MSCT score, calcium phosphate product, intact parathyroid hormone, vitamin D, triglycerides and fetuin-A, and there was no correlation between fetuin-A levels, age, dialysis duration and calcium phosphate product but a significant correlations with vitamin D3 (P = 0.034), serum albumin (P = 0.002) was detected. Inverse correlation with hs-CRP was obtained. Patients with ischemic heart disease had numerically lower levels of fetuin-A (P = 0.427) and numerically higher MSCT score (P = 0.135). Patients with low hs-CRP (<10) had numerically higher fetuin-A levels (P = 0.090) and significantly low MSCT scores (P = 0.020). Calcium deposition seen on MSCT increases with age and duration of dialysis but is not related to fetuin-A levels. Inconclusive relationship exists with other parameters of CKD-MBD. Large controlled studies are needed to establish the role of fetuin-A in vascular calcification in Indian population.

Plasma chemistry before and after two consecutive days of racing in sled dogs: associations between muscle damage and electrolyte status

Exercising long distance endurance sled dogs display plasma biochemistry changes characterised by elevations in creatine kinase (CK) and aspartate aminotransferase (AST), hypoproteinemia, hypoglobulinemia and decreases in sodium and potassium. The aim of this study was to compare resting to day 2 racing plasma biochemistry and associations between electrolytes and markers of muscle damage in well-conditioned sled dogs during a stage-stop race. Blood samples were obtained from 23 dogs prior to the start and on day 2, immediately after racing. Results showed significant decreases in potassium (day 0 – 4.7±0.3 and day 2 – 4.2±0.3 mEq/l), total protein (day 0 – 6.0±0.3 and day 2 – 5.5±0.4 g/dl) and albumin concentrations (day 0 – 3.9±0.2 and day 2 – 3.6±0.3 g/dl). Increases in AST (day 0 – 24±7 and day 2 – 137±97 U/l) and CK activities (day 0 – 129±39 and day 2 – 2,047±2,021 U/l) were also observed. Plasma sodium concentrations were not significantly different after day 2 of racing (day 0 – 153±5.2 and day 2 – 151±4.1). Alterations in plasma electrolytes, and increases in AST, CK, alanine aminotransferase and urea nitrogen were similar to those observed in long distance endurance sled dogs. A strong negative association was observed between plasma potassium and increases in plasma CK activity on day 2 (R2=0.69). The maintenance of sodium concentrations with a concurrent potassium decline, suggests sodium conservation via the renin-angiotensin-aldosterone pathway as previously shown in endurance sled dogs. The negative correlation between muscle damage and plasma potassium warrants further investigation regarding its relationship to rhabdomyolysis.

Motivated to do well: an examination of the relationships between motivation, effort, and cognitive performance in schizophrenia

The uncertain relationship between negative symptoms, and specifically motivational deficits, with cognitive dysfunction in schizophrenia is in need of further elucidation as it pertains to the interpretation of cognitive test results. Findings to date have suggested a possible mediating role of motivational deficits on cognitive test measures, although findings from formal examinations of effort using performance validity measures have been inconsistent. The aim of this study was to examine the relationships between motivation, effort exerted during cognitive testing, and cognitive performance in schizophrenia. Sixty-nine outpatients with schizophrenia or schizoaffective disorder were evaluated for psychopathology, severity of motivational deficits, effort exerted during cognitive testing, and cognitive performance. Motivation and degree of effort exerted during cognitive testing were significantly related to cognitive performance, specifically verbal fluency, verbal and working memory, attention and processing speed, and reasoning and problem solving. Further, effort accounted for 15% of the variance in cognitive performance, and partially mediated the relationship between motivation and cognitive performance. Examining cognitive performance profiles for individuals exerting normal or reduced effort revealed significant differences in global cognition, as well as attention/processing speed and reasoning and problem solving. These findings suggest that cognitive domains may be differentially affected by impairments in motivation and effort, and highlight the importance of understanding the interplay between motivation and cognitive performance deficits, which may guide the appropriate selection of symptom targets for promoting recovery in patients.

Impact of dietary plane of energy during the dry period on lipoprotein parameters in the transition period in dairy cattle

The high energy demands of dairy cows during the transition period from late gestation into early lactation can place them at an increased risk for the development of metabolic and infectious diseases. Modification of the dry period diet has been investigated as a preventive means to minimize the detrimental aspects of metabolic shifts during the transition period. Studies investigating the impact of dry period diet on lipid parameters during the transition period have largely focused on markers of lipolysis and ketogenesis. Total cholesterol declines during the periparturient period and increases in early lactation. The impact total energy in the dry period diet has on the ability of the cow to maintain total serum cholesterol, as well as its natural high-density lipoprotein-rich status, during this metabolically challenging window is not clear. The impact of lipoproteins on inflammation and immune function may have a clinical impact on the cow's ability to ward off production-related diseases. In this study, we hypothesized that the provision of adequate, but not excessive, total metabolizable energy, would better allow the cow to maintain total cholesterol and a higher relative proportion of HDL throughout the transition period. Cows were allocated to one of three dry period dietary treatment groups following a randomized block design. Total serum triglycerides, cholesterol and lipoprotein fractions were measured on a weekly basis from approximately 7 weeks pre-calving to 6 weeks post-calving. The cows on the high energy diet maintained total serum cholesterol as compared to the cows provided a lower energy diet, but there was no significant increase in the LDL fraction of lipoproteins between diet treatment groups.

Genetic algorithm based feature selection combined with dual classification for the automated detection of proliferative diabetic retinopathy

Proliferative diabetic retinopathy (PDR) is a condition that carries a high risk of severe visual impairment. The hallmark of PDR is the growth of abnormal new vessels. In this paper, an automated method for the detection of new vessels from retinal images is presented. This method is based on a dual classification approach. Two vessel segmentation approaches are applied to create two separate binary vessel map which each hold vital information. Local morphology features are measured from each binary vessel map to produce two separate 4-D feature vectors. Independent classification is performed for each feature vector using a support vector machine (SVM) classifier. The system then combines these individual outcomes to produce a final decision. This is followed by the creation of additional features to generate 21-D feature vectors, which feed into a genetic algorithm based feature selection approach with the objective of finding feature subsets that improve the performance of the classification. Sensitivity and specificity results using a dataset of 60 images are 0.9138 and 0.9600, respectively, on a per patch basis and 1.000 and 0.975, respectively, on a per image basis.

[Brain death diagnosis after sedation with propofol or sufentanil. Recommendations for the usage of toxicological analytics]

BACKGROUND

Before the clinical diagnosis of brain death is made, toxicological analyses are often performed for the exclusion of effective serum levels of previously applied sedating drugs. For propofol and sufentanil there are no uniform recommendations for the usage of toxicology test results.

OBJECTIVES

To develop a standard practice in the diagnosis of brain death after therapeutic application of one of these drugs.

MATERIAL AND METHODS

Based on the current literature and the available analytical assays, an ad hoc working group consisting of specialists in toxicology and intensive care medicine compiled recommendations for the usage of toxicological analytics in the diagnosis of brain death at the Rostock University Hospital.

RESULTS

For propofol, current analytical assays allow the quantification of serum concentrations of 0.2 μg/ml and lower; the execution of clinical brain death diagnostics is recommended by the ad hoc group only at propofol serum levels lower than  0.4 μg/ml. For sufentanil, the currently prevalent assays set lower determination limits of about 0.2 ng/ml in serum and 0.1 ng/ml in urine, which is above the cautiously adopted lower therapeutic serum concentration of 0.02 ng/ml. Therefore after negative determination of sufentanil (< 0.2 ng/ml) in blood serum, the following alternative procedures are recommended: (1) the execution of clinical brain death diagnostics under administration of naloxone; or (2) at intact renal function the additional negative determination of sufentanil in urine (< 0.1 ng/ml). If an assay allowing the detection of sufentanil at ≤ 0.01 ng/ml is available, brain death diagnostics should be carried out only at a serum level lower than  0.02 ng/ml.

CONCLUSION

These recommendations may serve as a proposal for similar standards in other hospitals.