Early morphological and neurochemical changes of the bed nucleus of stria terminalis (BNST) in gestational protein-restricted male offspring.

BACKGROUND: The bed nucleus of the stria terminalis (BNST) is a structure with a peculiar neurochemical composition involved in modulating anxietylike behavior and fear. AIM: The present study investigated the effects on the BNST neurochemical composition and neuronal structure in critical moments of the postnatal period in gestational protein-restricted male rats' offspring. METHODS: Dams were maintained during the pregnancy on isocaloric rodent laboratory chow with standard protein content [NP, 17%] or low protein content [LP, 6%]. BNST from male NP and age-matched LP offspring was studied using the isotropic fractionator method, Neuronal 3D reconstruction, dendritic-tree analysis, blotting analysis, and high-performance liquid chromatography. RESULTS: Serum corticosterone levels were higher in male LP offspring than NP rats in 14-day-old offspring, without any difference in 7-day-old progeny. The BNST total cell number and anterodorsal BNST division volume in LP progeny were significantly reduced on the 14th postnatal day compared with NP offspring. The BNST HPLC analysis from 7 days-old LP revealed increased norepinephrine levels compared to NP progeny. The BNST blot analysis from 7-day-old LP revealed reduced levels of GR and BDNF associated with enhanced CRF1 expression compared to NP offspring. 14-day-old LP offspring showed reduced expression of MR and 5HT1A associated with decreased DOPAC and DOPA turnover levels relative to NP rats. In Conclusion, the BNST cellular and neurochemical changes may represent adaptation during development in response to elevated fetal exposure to maternal corticosteroid levels. In this way, gestational malnutrition alters the BNST content and structure and contributes to already-known behavioral changes.

Functional fitness of adults with Down syndrome: a longitudinal study.

BACKGROUND: Individuals with Down syndrome (DS) are born with and develop many health-related complications. The purpose of this study was to determine the longitudinal functional fitness profile of adults with DS. METHODS: The functional fitness of adults with DS was tested twice, 12 years apart. Sixty-six adults with DS were tested for body mass, stature and 10 functional fitness tests. Data were categorised according to gender and age-specific categories. RESULTS: Static balance, shoulder flexibility, trunk strength and aerobic capacity deteriorated significantly with medium to large effect sizes for both DS men and women (most age categories). For women, dynamic balance deteriorated significantly, and for men, leg- and upper body-strength deteriorated significantly. CONCLUSIONS: Practitioners working in the field of adapted physical activity should take cognisance of the functional fitness ageing profile of adults with DS and timeously develop habitual physical activity interventions to reduce the effect of accelerated ageing experienced by this population.

The effect of 8 weeks of freestyle swim training on the functional fitness of adults with Down syndrome.

BACKGROUND: Studies conducted on adults with Down syndrome have demonstrated the improvement of functional fitness (aerobic capacity, muscular strength, balance, flexibility, functional ability, body mass or body mass index) with varying exercise modalities but often with one or two components in isolation. Such modalities included walking, running, cycling, rowing or resistance training. Freestyle swim training has shown significant improvements of all parameters associated with functional fitness in the general population. Swimming is an aerobic activity where many of the large muscle groups are involved and may provide more functional fitness benefits. As a consequence, the purpose of our study was to investigate the effect of freestyle swim training on the functional fitness of adults with Down syndrome. METHODS: Twenty-six adults with Down syndrome (33 ± 6 years; 34 ± 9 kg/m2 ) were randomly allocated to an exercise (n = 13; 81.3 kg) or control group (n = 13; 81.5 kg). The exercise group performed 8 weeks of freestyle swim training, three times a week, 30 min per session (increased to 40 min after 4 weeks). To evaluate differences between groups, a one-way analysis of variance was used, controlling for differences at baseline. RESULTS: After 8 weeks of training, the results showed significant differences between the exercise and control group for body mass, body mass index, aerobic capacity, dynamic balance, muscular strength, 12-m swim time and functional ability (P < 0.05). Effect sizes ranged from small to large. CONCLUSIONS: Various components of functional fitness improved significantly after an intervention period of freestyle swim training. The collective improvement of many functional fitness parameters shown by this study may hold benefits for these often-neglected and in many cases functionally impaired individuals.

Effects of detraining on anthropometry, aerobic capacity and functional ability in adults with Down syndrome.

BACKGROUND: Structured exercise has shown to improve parameters of functional fitness in adults with Down syndrome (DS). However, few, if any, continue to exercise after exercise intervention studies. Consequently, the purpose of this study was to determine the effects of detraining on anthropometry, aerobic capacity and functional ability of adults with DS. METHODS: In a previous study, forty-two participants either performed 12 weeks of interval training, continuous aerobic training or no training (CON). After 3 months of detraining, the same participants were tested again for anthropometry, aerobic capacity, leg strength and functional ability. RESULTS: Significant reductions in maximal aerobic capacity, time to exhaustion and both functional test items were reported for both exercise groups compared to CON (p < .05). No significant differences were reported between the exercise groups concerning aerobic and functional capacity reductions. CONCLUSION: Detraining occurred significantly in both exercise groups regarding parameters associated with aerobic and functional capacity.

Accuracy of the prediction equation for the determination of maximum heart rate in adults with Down syndrome.

BACKGROUND: The purpose of the study was to determine if the regression formula developed for the prediction of maximum heart rate (HR) is valid for adults with Down syndrome (DS). METHODS: Thirty-six adults with DS (31.7 ± 6.8 years; 20 men, 16 women) completed a maximal aerobic test. Maximum HR and VO2 peak were measured directly on a motorised treadmill with a metabolic analyser. Predicted HR was estimated with the regression equation developed for individuals with DS (Fernhall et al. 2001). Differences between measured versus predicted maximum HR were assessed with a dependent T-test and the relationship with Pearson correlational analyses. Agreement was assessed with Bland-Altman analysis. RESULTS: There was a significant difference between directly measured maximum HR and predicted maximum HR (P < 0.01). There was no significant relationship between these variables. Bland-Altman analysis indicated that there was measurement bias (+4.7) and large limits of agreement (+26.7 and -17.4) between measured and predicted maximum HR. The Bland-Altman plot also demonstrated the presence of heteroscedasticity. CONCLUSIONS: The results indicate that the regression formula developed for individuals with DS was not accurate in this sample of DS adults aged 19 to 46 years. Future studies should develop different prediction equations for more specific age and body mass index categories for individuals with DS.

Effect of continuous aerobic vs. interval training on selected anthropometrical, physiological and functional parameters of adults with Down syndrome.

BACKGROUND: A large percentage of adults with Down syndrome (DS) are overweight and have extremely low aerobic capacities compared with the general population and persons with intellectual disability without DS. Previous aerobic training intervention studies showed limited potential to significantly ameliorate anthropometrical and cardiovascular variables. The primary purpose of this study was to determine the effect of continuous aerobic training (CAT) vs. interval training (IT) on selected anthropometrical, health, physical and functional parameters of adults with DS. METHODS: Forty-two adults with DS (25 men and 17 women) and a mean age of 33.8 (±8.6) years were randomly allocated to one of three groups (IT, CAT and control). Training was performed for 12 weeks. The IT group performed 10-30 s all out sprints with 90 s (1:3 work-rest ratio) of low cadence, low intensity cycling or walking. The CAT group performed continuous cycling and walking at an intensity of 70-80% of VO2 peak. Heart rate monitors were used for monitoring training intensities. After 6 weeks of training, the intensity of the CAT was increased to 85% of VO2 peak, whilst the intensity of the IT group remained 'all out'. An increase of 5 min in duration was implemented after 6 weeks for both training groups. To evaluate pre-post differences between groups, a repeated analysis of covariance with post hoc Bonferroni test was performed RESULTS: After 12 weeks of training, body weight and body mass index decreased significantly more in the IT group compared with control and CAT (P < 0.05). Participants in the IT group decreased their body weight from 71.4 ± 8 to 69.4 ± 8 kg and their body mass index from 29.3 ± 4 to 28.5 ± 4 kg/m2 . Significant ameliorations for functional parameters and leg strength were shown for CAT compared with control (P < 0.05). Participants in the CAT group improved their performance in the 6 minute walk distance (499 ± 78 to 563 ± 75 m), 8-ft up-and-go (5.9 ± 1.2 to 4.8 ± 0.9) and leg strength (13.1 ± 2 to 15.2 ± 2). VO2 peak and time to exhaustion significantly improved in both the IT and CAT group compared with control (P < 0.01). Moreover, a significant improvement for relative VO2 peak was also determined for IT compared with CAT (P < 0.05). Participants in the IT group increased their VO2 peak from 32 ± 8 to 37 ± 8 mL/min/kg. Submaximal heart rate and VO2 values improved significantly within both exercise groups (P < 0.05). CONCLUSION: Interval training and CAT can both be pursued by adults with DS to positively impact on various parameters of anthropometry, fitness and functional ability, with IT more appropriate for improving body weight and aerobic capacity.

Real-time PCR detection of Campylobacter spp.: A comparison to classic culturing and enrichment.

The major disadvantage of the current gold standard for detection of the food pathogen Campylobacter, i.e. culturing, is the lengthy procedure. In this study we assessed the use of real-time PCR for detection of Campylobacter. To this end, 926 poultry samples, taken from transport containers and broiler caeca in The Netherlands in 2007, were subjected to three different real-time PCR detection methods: one targeting the Campylobacter jejuni hipO gene, one targeting the Campylobacter coli glyA gene, and one generically targeting Campylobacter spp. 16S rDNA sequence. The PCR results from the three different PCR protocols were compared to the work of Nauta et al. (2009) who analyzed the same set of samples collected from 62 broiler flocks by means of enrichment culturing. The results indicate that the generic 16S campylobacter PCR detection is equally reliable but much faster (4 h instead of ≥2 days) than detection by means of culturing. Moreover, PCR detection targeting the hipO and the glyA gene provide the possibility of C. jejuni and C. coli species discrimination. The generic Campylobacter spp. PCR analysis also confirmed the high incidence of Campylobacter spp. in poultry samples (∼90%) and the species specific PCR showed the simultaneous presence of C. jejuni and C. coli in ∼24% of the samples. Furthermore, the results from the three PCR analyses suggested the occurrence of alternative Campylobacter species in almost 10% of the samples. The campylobacter PCR detection methods reported here can replace traditional culturing because of being quicker and more reliable.

The functional fitness capacity of adults with Down syndrome in South Africa.

BACKGROUND: It is well established that there is a relationship between physical inactivity and increased risk for diseases of lifestyle. Persons with Down syndrome (DS) are especially at risk because of physical and health impairments, as well as perceived and real barriers to participation in exercise. The purpose of the study was to establish the functional fitness capacity and predictors of performance of DS adults. METHODS: Data were collected at various intellectual disability centres and private homes in seven provinces of South Africa. Three hundred and seventy-one DS individuals (199 men and 172 women) from 18 to 66 years were tested for balance, flexibility, coordination, muscular strength and endurance, aerobic capacity and functional ability. Data were categorised according to gender and age groups (18-25, 26-35, 36-45, and >45 years). Multiple regression analysis was performed to determine the relationship between the functional task and physical test items. RESULTS: Down syndrome men performed significantly better on all but two tests compared with the women (P < 0.05). DS women performed better on the sit-and-reach flexibility item and the chair stand test; however, differences were not statistically significant from the men. Significant differences across age groups were observed for nine of the 13 functional fitness tests (P < 0.05). Muscular strength items, especially leg strength, significantly predicted functional performance in DS men and women. Aerobic capacity only predicted functional performance in DS men and sit-and-reach flexibility and dynamic balance only in DS women. CONCLUSIONS: Findings of this study provide important information on the functional capacity of DS adults and show which physical attributes contribute to functional performance. Consequently appropriate training programmes can be tailored for this population whom is known to have poor functional fitness.

ATM and RPA in meiotic chromosome synapsis and recombination.

ATM is a member of the phosphatidylinositol 3-kinase (PIK)-like kinases, some of which are active in regulating DNA damage-induced mitotic cell-cycle checkpoints. ATM also plays a role in meiosis. Spermatogenesis in Atm-/- male mice is disrupted, with chromosome fragmentation leading to meiotic arrest; in human patients with ataxia-telangiectasia (A-T), gonadal atrophy is common. Immuno-localization studies indicate that ATM is associated with sites along the synaptonemal complex (SC), the specialized structure along which meiotic recombination occurs. Recombination, preceded by pairing of homologous chromosomes, is thought to require heteroduplex formation between homologous DNA, followed by strand exchange. These early meiotic steps (entailing the formation and processing of meiotic recombination intermediates with DNA-strand interruptions) require ssDNA-binding proteins such as replication protein A (RPA; refs 5-7). In somatic cells, DNA damage induces ATM-dependent phosphorylation of RPA. We demonstrate here that ATM and RPA co-localize along synapsed meiotic chromosomes and at sites where interactions between ectopic homologous chromosome regions appear to initiate. In Atm-/- meiotic prophase spermatocytes, immuno-localization shows that RPA is present along synapsing chromosomes and at sites of fragmentation of the SC. These results suggest that RPA and ATM co-localize at sites where interhomologous-DNA interactions occur during meiotic prophase and where breaks associated with meiotic recombination take place after synapsis, implying a possible functional interaction between these two proteins.

Recombinational DNA double-strand breaks in mice precede synapsis.

In Saccharomyces cerevisiae, meiotic recombination is initiated by Spo11-dependent double-strand breaks (DSBs), a process that precedes homologous synapsis. Here we use an antibody specific for a phosphorylated histone (gamma-H2AX, which marks the sites of DSBs) to investigate the timing, distribution and Spo11-dependence of meiotic DSBs in the mouse. We show that, as in yeast, recombination in the mouse is initiated by Spo11-dependent DSBs that form during leptotene. Loss of gamma-H2AX staining (which in irradiated somatic cells is temporally linked with DSB repair) is temporally and spatially correlated with synapsis, even when this synapsis is 'non-homologous'.

Operative versus non-operative treatment for two-part surgical neck fractures of the proximal humerus.

INTRODUCTION: Aim of this study was to evaluate outcomes of operative as compared to conserveative treatment for two-part humerus fractures at the surgical neck. METHODS: Data from a prospective multi-centre cohort study on four treatment options (conservative treatment and three implants, i.e. LPHP, PHILOS and PHN) for proximal humerus fractures were evaluated in this post hoc analysis. All patients with two-part fractures of the surgical neck (AO types A2, n = 54 and A3, n = 110) were identified and included for the analysis. All operatively treated patients were gathered and compared to those receiving conservative treatment. Primary outcome parameters were pain, range of motion and absolute and relative Constant scores at 3, 6 and 12 months following injury and coronal plane alignment at 12 months. RESULTS: Operative (n = 133) and non-operative (n = 31) groups were comparable with regard to all parameters assessed including mean age (62.9 vs. 65.6, P = 0.479), gender (27 vs. 29 % male, P = 0.826) and fracture distribution (65 vs. 77 % A3 type, P = 0.207). 26 of the 31 conservatively treated and 103 of the 133 operatively treated patients (84 and 77 %, respectively) were available for final follow-up. There was a continuous improvement for all outcome parameters in both treatment groups (P < 0.001). Operative treatment resulted in a more effective reduction of pain at 3 months (51 vs. 76 % reporting pain at fracture site, P = 0.03) and a reduction of coronal plane malalignment. Both range of motion and Constant scores were, however, comparable in both groups at all follow-up visits. Relative and absolute Constant scores were generally excellent at final follow-up (74 vs. 74, P = 0.528 and 89 vs. 91, P = 0.494, respectively). CONCLUSIONS: Both non-operative treatment and operative treatment using modern implants (LPHP, PHILOS and PHN) can be considered safe and effective treatment options for two-part fractures of the proximal humerus. Operative treatment may result in better range of motion and reduced pain in the early postoperative course of treatment.

Chromosome segregation and cytokinesis in bacteria.

Substantial progress has recently been made in the understanding of chromosome partitioning and cytokinesis in bacteria. The biochemical properties of some key protein components involved in these processes are beginning to emerge. New evidence supports the recently developed notion that, in prokaryotic cells, basic cell biological processes rely on the activity of previously unidentified cytoskeletal-like elements.

Improvement in chromatin maturity of human spermatozoa selected through density gradient centrifugation.

A two-step gradient density centrifugation system has been set up to isolate two contrasting sperm populations of normozoospermic and oligoasthenoteratozoospermic (OAT) men. High- and low-density fractions were characterized by total and free thiol fluorescence as determined by monobromobimane-flow cytometry and by protamine/DNA ratios after protamine extraction and polyacrylamide acid-urea gel electrophoresis. Further chromatin characterization was performed through immunofluorescence (IF) with specific antibodies to nucleosomes, histone subtypes (H3.1/H3.2 and TH2B), histone modifications (KM-2 and H4K8ac) and precursor protamine 2. The native sperm samples from normozoospermic and OAT patients showed a biphasic distribution of total thiol levels, which changed in the sperm fractions obtained using the density isolation protocol presented here. Moreover, significant differences were detected in the protamine content in the different fractions of OAT and fertile donor samples. In addition, in the high-density fractions from OAT and normozoospermics, higher IF levels for H4K8ac and TH2B were seen. These results would be consistent with the intended beneficial effect on chromatin maturity of the density selection techniques currently being used in assisted fertilization procedures. However, most nucleosome and related proteins/modifications differ between OAT and normozoospermic men, even after gradient centrifugation, providing evidence for incomplete nuclear maturity in OAT patients.

In vivo repair of DNA damage induced by X-rays in the early stages of mouse fertilization, and the influence of maternal PARP1 ablation.

The early pronucleus stage of the mouse zygote has been characterised in vitro as radiosensitive, due to a high rate of induction of chromosome-type chromosome abnormalities (CA). We have investigated the repair of irradiation induced double strand DNA breaks in vivo by γH2AX foci and first cleavage metaphase analysis. Breaks were induced in sperm and in the early zygote stages comprising sperm chromatin remodelling and early pronucleus expansion. Moreover, the role of PARP1 in the formation and repair of spontaneous and radiation-induced double strand breaks in the zygote was evaluated by comparing observations in C57BL/6J and PARP1 genetically ablated females. The results confirmed in vivo that the rate of chromosome aberration induction by X-rays was approximately 3-fold higher in the zygote than in mouse lymphocytes. This finding was related to a diminished efficiency of double strand break signalling, as shown by a lower rate of γH2AX radiation-induced foci compared to that measured in most other somatic cell types. The spontaneous frequency of CA in PARP1 depleted zygotes was slightly but significantly higher than in wild type zygotes. Also, these zygotes showed some impairment of the radiation-induced DNA Damage Response when exposed closer to the start of S-phase, revealed by a higher number of γH2AX foci and a longer cell cycle delay. The rate of chromosome aberrations, however, was not elevated over that of wild type zygotes, possibly thanks to backup repair pathways and/or selection mechanisms against damaged cells. When comparing with the literature data on irradiation induced CA in mouse zygotes in vitro, the levels of induction were strikingly similar as was the frequency of misrepair of double strand breaks (γH2AX foci). This result can be reassuring for in vitro human gamete and embryo handling, because it shows that culture conditions do not significantly affect double strand DNA break repair.

Memoirs of an insult: sperm as a possible source of transgenerational epimutations and genetic instability.

Male transgenerational epigenetic effects have been discovered in the discipline of mouse radiation genetics, using genetic and non-genetic readouts. The mechanism to explain the origin of the transmission of epigenetic and genetic instability is still unknown. In a search for a hypothesis that could satisfy the data, we propose that regulation of chromosome structure in the germline, by the occupancy of matrix/scaffold associated regions, contains molecular memory function. The male germline is strikingly dynamic as to chromatin organization. This could explain why experience of irradiation stress leaves a persistent mark in the male germline only. To be installed, such memory requires both S-phase and chromatin reorganization during spermatogenesis and in the zygote, that likely also involves reorganization of loop domains. By this reorganization, another layer of information is added, needed to accommodate early embryonic development. Observations point at the involvement of DNA repair as inducer of transgenerational epigenetic modulation. Nuclear structure, chromatin composition and loop domain organization are aspects of human sperm variability that in many cases of assisted reproduction is increased due to inclusion of more incompletely differentiated/maturated sperm nuclei. Adjustment of loop domains in early embryo development can be anticipated and zygotic and cleavage stage S-phase repair activity will have to deal with potential paternal DNA lesions. Therefore, by changing male nucleus structure due to reproduction from impaired spermatogenesis, the transgenerational information content could be changed as well. We discuss aspects of male reproductive performance in the context of this hypothesis.

The distinction between retractor and protractor muscles of the freshwater snail's male organ has no physiological basis.

Many animals are equipped with organs that can be everted, a notable example being male copulatory organs. The ability to protrude or evert an organ generally requires protractor and retractor muscles. Male copulatory behaviour of the pond snail Lymnaea stagnalis (L.) involves eversion (protraction) and retraction of the relatively large penis-carrying organ. For this preputium, protractor and retractor muscle bands have been defined, which implies eversion and retraction through the activity of these muscle bands. However, no physiological data are available that confirm that the terms protractor and retractor are appropriate. To test whether eversion and retraction are possible without protractor and/or retractor muscle bands, lesion experiments were performed. The results show that with either one or several muscle bands lesioned, snails were still capable of everting their preputium and using it for copulation. However, the majority of animals that had six or more muscle bands lesioned were unable to retract its preputium. Hence, retractor muscle bands serve their designated function whereas protractor muscle bands do not. We therefore suggest that a different terminology is used in which all muscle bands are retractors and, based on their location, are either called distal or proximal retractors. The findings furthermore indicate that the preputium muscle bands are normally contracted, possibly in a catch state, retaining the organ inside without high-energy expenditure.

Constitutional DNA copy number changes in ICSI children.

BACKGROUND: Over the last three decades, technological developments facilitating assisted reproductive techniques (ART) have revolutionized the treatment of subfertile couples, including men suffering from severe oligospermia or azoospermia. In parallel with the advent of these technologies, there is a great concern about the biological safety of ART. This concern is supported by the clinical observation that the frequency of congenital malformations is slightly elevated among ART-conceived children. METHODS: In this explorative study, we have used tiling-resolution BAC array-mediated comparative genomic hybridization to investigate the incidence of de novo genomic copy number changes in a group of 12 ICSI children, compared with a control group of 30 naturally conceived children. RESULTS: In 6 of the 12 ICSI children, we found 10 apparently de novo 'same direction genomic copy number changes' [i.e. simultaneous copy number gain (or loss) with respect to both biological parents], notably losses. In statistically significant contrast, similar observations were encountered only six times in the control group in 5 of the 30 children. However, our study group was small, so a larger group is needed to confirm these findings. CONCLUSIONS: Loci at which we found de novo alterations are known from the human genome database to be prone to large DNA segment copy number changes. As discussed, various molecular mechanisms, including the consequences of delayed male meiotic synapsis and replication fork stalling at early embryonic cell cycles, might trigger these copy number changes.

Parental origin of chromatin in human monopronuclear zygotes revealed by asymmetric histone methylation patterns, differs between IVF and ICSI.

In mouse zygotes, many post-translational histone modifications are asymmetrically present in male and female pronuclei. We investigated whether this principle could be used to determine the genetic composition of monopronuclear human zygotes in conventional IVF and ICSI. First we determined whether male female asymmetry is conserved from mouse to human by staining polypronuclear zygotes with antibodies against a subset of histone N-tail post-translational modifications. To analyze human monopronuclear zygotes, a modification, H3K9me3, was selected that is present in the maternal chromatin. After IVF a total of 45 monopronuclear zygotes were obtained. In 39 (87%) of zygotes a nonuniform staining pattern was observed, proof of a bi-parental origin and assumed to result into a diploid conception. Two zygotes showed no staining for the modification, indicating that the single pronucleus was of paternal origin. Four zygotes contained only maternally derived chromatin. ICSI-derived monopronuclear zygotes (n = 33) could also be divided into three groups based on the staining pattern of their chromatin: (1) of maternal origin (n = 15), (2) of paternal origin (n = 8) or (3) consisting of two chromatin domains as dominating in IVF (n = 10). Our data show that monopronuclear zygotes originating from IVF generally arise through fusion of parental chromatin after sperm penetration. Monopronuclear zygotes derived from ICSI in most cases contain uni-parental chromatin. The fact that chromatin was of paternal origin in 24% of ICSI and in 4% of the IVF zygotes confirms earlier results obtained by FISH on cleavage stages. Our findings are of clinical importance in IVF and ICSI practice.