Impairment of schedule-controlled behavior by pre- and postnatal exposure to hexachlorobenzene in rats

 Hexachlorobenzene (HCB) is still frequently found at elevated levels in human adipose tissue and breast milk. As intoxication with HCB causes neurological disturbance in human beings, the purpose of the present study was to examine neurobehavioral functions in rats after pre- and postnatal exposure. Female rats were fed diets with 0, 4, 8, or 16 mg HCB/kg diet. Exposure started 90 days prior to mating and was continued throughout mating, gestation, and lactation. Thereafter, the offspring were given the same diets as their respective mothers. HCB levels were determined in the brain, the liver, and in the adipose tissue from virgin rats, dams, and the offspring. Concentrations on a lipid basis were found to decline in the order adipose>liver>brain. The exposure levels chosen did not cause gross toxic effects in dams or offspring. There were dose-related increases in liver-to-body-weight ratios in exposed dams, but not in unmated females treated alike. Behavioral testing was conducted in the offspring. Examination of open-field activity on PND 21, and of active avoidance learning on PND 90 failed to reveal significant differences between groups. Training of operant behavior started at the age of 150 days in the offspring from the control, the 8-mg group, and the 16-mg group. Animals were trained on a fixed interval schedule of 1 min (FI-1). On this schedule, responses were reinforced by a food pellet every time 1 min had elapsed after the preceding reinforcement. There were dose-dependent reductions in the post-reinforcement pause, e.g. the time between each reinforcement and the first reaction emitted after it. In addition, the index of curvature, which describes the efficiency of performance on the FI-1 schedule, was decreased in a dose-dependent fashion. Received: 12 April 1994 / Accepted: 26 June 1995     

Polymere ammoniumsalze aus N,N,N′,N′-tetramethylalkylendiaminen und N,N′-alkylenbis(chloracetamid)en

Long chain polymeric ammonium salts 3a–g and 4a were prepared in DMF/H₂O from N,N,N′,N′-tetramethylalkylenediamines 2a and 2b and N,N′-alkylenebis(chlorocetamide)s 1a–g . Some of them can be casted to clear transparent sheets. The chlorine atoms in 1a – g are activated by the adjacent carbonyl amino group. The polymer from N,N′-tetramethylenebis(chloroacetamide) ( 1d ) and N,N,N′,N′-tetramethylhexamethylenediamine (2b) shows an intrinsic viscosity of 61 ml/g, the highest value known for polyelectrolytes so far. The intrinsic viscosity decreases with increasing numbers of CH₂-groups in the monomers. The polymeric ammonium salts 3a – g and 4a give sheets from DMF solutions, which are soluble in water and stable under normal conditions. Polymers which are best suitable for the preparation of sheets show less hygroscopicity than the others, due to their structure. Intrinsic viscosities were calculated from the reduced specific viscosities measured in 0,4 _M KCl but may be also determined in water by the method of Yuan et al., plotting the reduced specific viscosities as a function of 1/√c.     

Epitope analysis with monoclonal antibodies directed against class II molecules subdivides HLA-DR2, DR3 and DR4: correlations with cellularly defined Dw specificities

Monoclonal antibodies (Mabs) defining 14 distinct polymorphic epitopes have been produced against the class II antigens of HLA-DR3Dw3DQw2 cells. Population analysis indicates that Mab C1 is directed against the DQw2 specificity and Mab M6 against the DRw52 specificity. The remaining Mabs define epitopes shared by the class II molecules of DR3 and various other specificities. Seven DR3Dw3DQw2 haplotypes were examined and could be divided into two types based on the presence of the epitope defined by Mab M3. Analysis of DR2 and DR4 homozygous cells with these Mabs revealed several distinct patterns of epitope expression. These subdivisions were found to correlate with the cellularly defined Dw specificities.     

Exploratory Efficacy of Calcium-Vitamin D Milk Fortification and Periodontal Therapy on Maternal Oral Health and Metabolic and Inflammatory Profile

In this 2 × 2 factorial, outcome-assessor blinded, feasibility randomised trial we explored the effect of a non-pharmaceutical multi-component intervention on periodontal health and metabolic and inflammatory profiles among pregnant women with periodontitis receiving prenatal care in a Brazilian public health centre. 69 pregnant women (gestational age ≤20 weeks, T0) were randomly allocated into four groups: (1) fortified sachet (vitamin D and calcium) and powdered milk plus periodontal therapy during pregnancy (early PT) (n = 17); (2) placebo sachet and powdered milk plus early PT (n = 15); (3) fortified sachet and powdered milk plus late PT (after delivery) (n = 19); (4) placebo sachet and powdered milk plus late PT (n = 18). Third trimester (T1) and 6–8 weeks postpartum (T2) exploratory outcomes included periodontal health (% sites with bleeding on probing (BOP)), glucose, insulin, C-Reactive Protein, serum calcium and vitamin D. The mean BOP was significantly reduced in the early PT groups, while BOP worsened in the late PT groups. No significant effect of fortification on BOP was observed. Changes in glucose levels and variation on birthweight did not differ among groups This feasibility trial provides preliminary evidence for estimating the minimum clinically important differences for selected maternal outcomes. A large-scale trial to evaluate the interventions’ clinical benefits and cost-effectiveness is warranted.     

The H2020 “NoHoW Project”: A Position Statement on Behavioural Approaches to Longer-Term Weight Management

There is substantial evidence documenting the effects of behavioural interventions on weight loss (WL). However, behavioural approaches to initial WL are followed by some degree of longer-term weight regain, and large trials focusing on evidence-based approaches to weight loss maintenance (WLM) have generally only demonstrated small beneficial effects. The current state-of-the-art in behavioural interventions for WL and WLM raises questions of (i) how we define the relationship between WL and WLM, (ii) how energy balance (EB) systems respond to WL and influence behaviours that primarily drive weight regain, (iii) how intervention content, mode of delivery and intensity should be targeted to keep weight off, (iv) which mechanisms of action in complex interventions may prevent weight regain and (v) how to design studies and interventions to maximise effective longer-term weight management. In considering these issues a writing team within the NoHoW Consortium was convened to elaborate a position statement, and behaviour change and obesity experts were invited to discuss these positions and to refine them. At present the evidence suggests that developing the skills to self-manage EB behaviours leads to more effective WLM. However, the effects of behaviour change interventions for WL and WLM are still relatively modest and our understanding of the factors that disrupt and undermine self-management of eating and physical activity is limited. These factors include physiological resistance to weight loss, gradual compensatory changes in eating and physical activity and reactive processes related to stress, emotions, rewards and desires that meet psychological needs. Better matching of evidence-based intervention content to quantitatively tracked EB behaviours and the specific needs of individuals may improve outcomes. Improving objective longitudinal tracking of energy intake and energy expenditure over time would provide a quantitative framework in which to understand the dynamics of behaviour change, mechanisms of action of behaviour change interventions and user engagement with intervention components to potentially improve weight management intervention design and evaluation.     

Impact of rate versus rhythm control on quality of life in patients with persistent atrial fibrillation. Results from a prospective randomized study.

AIMS: Despite the high prevalence of atrial fibrillation (AF), there are only limited data on quality of life (QoL) stemming from prospective trials comparing rate versus rhythm control. This prospective study evaluated QoL in patients with symptomatic persistent AF randomized to therapy aiming at rate versus rhythm control. METHODS AND RESULTS: Patients with symptomatic persistent AF (7 to 360 days duration) were prospectively randomized to ventricular rate control (n=125) or to cardioversion and maintenance of sinus rhythm (n=127). QoL was assessed by the Medical Outcomes Study Short Form health survey (SF-36) at baseline and during 1 year of follow-up. Changes in QoL were compared on an intent-to-treat basis, and subsequently between patients in sinus rhythm versus AF. At baseline, all SF-36 scales were reduced compared to healthy controls. At 1 year, six of eight items had improved significantly in patients assigned to rate control, and five of eight items on rhythm control (p=ns). The physical component summary showed a comparable increase with both treatment strategies (rate control: p=0.004; rhythm control: p<0.001) whereas no significant changes were found for the mental component summary. At 1 year, 55% of patients reported a positive health transition with no inter-group differences. There were no significant differences in QoL in patients in sinus rhythm or AF at the end of the observation period. CONCLUSION: In patients with symptomatic persistent AF, the two treatment strategies of rate versus rhythm control are associated with similar improvements in QoL.     

Evaluation of the ERIC-PCR as a probable method to differentiate Avibacterium paragallinarum serovars

Infectious coryza, an upper respiratory tract disease in chickens, caused by Avibacterium paragallinarum, leads to huge economic losses. The disease is controlled through vaccination; but vaccination efficacy is dependent on correct identification of the infecting serovar, as limited cross-protection is reported amongst some serovars. Current identification methods include the heamagglutination inhibition test, which is demanding and could be subjective. To overcome this, molecular typing methods proposed are the Multiplex polymerase chain reaction (PCR) and Restriction Fragment Length Polymorphism-PCR, but low reproducibility is reported. Enterobacterial Repetitive Intergenic Consensus (ERIC)-PCR has been suggested for molecular groupings of various bacterial species. This study focuses on evaluating the ERIC-PCR as a probable method to differentiate between different Av. paragallinarum serovars by grouping with reference isolates, based on clonal relations. The ERIC-PCR was performed on 12 reference isolates and 41 field isolates originating from South Africa and South America. The data indicate that the ERIC-PCR is not ideal for the differentiation or for molecular typing of Av. paragallinarum serovars, as no correlation is drawn upon comparison of banding patterns of field isolates and reference strains. However, the results do indicate isolates from the same origin sharing unique banding patterns, indicating potential clonal relationship; but when compared to the reference isolates dominant in the specific area, no correlation could be drawn. Furthermore, although the ERIC-PCR serves a purpose in epidemiological studies, it has proved to have little application in differentiating amongst serovars of Av. paragallinarum and to group untyped field strains with known reference strains.