Potential biological role of poly (ADP-ribose) polymerase (PARP) in male gametes

Maintaining the integrity of sperm DNA is vital to reproduction and male fertility. Sperm contain a number of molecules and pathways for the repair of base excision, base mismatches and DNA strand breaks. The presence of Poly (ADP-ribose) polymerase (PARP), a DNA repair enzyme, and its homologues has recently been shown in male germ cells, specifically during stage VII of spermatogenesis. High PARP expression has been reported in mature spermatozoa and in proven fertile men. Whenever there are strand breaks in sperm DNA due to oxidative stress, chromatin remodeling or cell death, PARP is activated. However, the cleavage of PARP by caspase-3 inactivates it and inhibits PARP's DNA-repairing abilities. Therefore, cleaved PARP (cPARP) may be considered a marker of apoptosis. The presence of higher levels of cPARP in sperm of infertile men adds a new proof for the correlation between apoptosis and male infertility. This review describes the possible biological significance of PARP in mammalian cells with the focus on male reproduction. The review elaborates on the role played by PARP during spermatogenesis, sperm maturation in ejaculated spermatozoa and the potential role of PARP as new marker of sperm damage. PARP could provide new strategies to preserve fertility in cancer patients subjected to genotoxic stresses and may be a key to better male reproductive health

Reconstruction of mixed-phase signals from sum-of-autotriplecorrelations using least squares

A least squares minimization technique for the reconstruction of a real, discrete-time signal from a sum-of-autotriplecorrelations (SOA) sequence is presented. Compared with other methods, our approach has many advantages. First, the reconstruction is based on simple one-dimensional (1-D), instead of two-dimensional (2-D), time-domain operations. Moreover, unlike some current methods, it is possible to perform the reconstruction even if the z transform of the signal has roots on the unit circle. We present the derivation of the approach and simulation results. © 1998 IEEE

Multi-scale deconvolution of sensor array signals

We present a novel solution to a 'hands-off' deconvolution problem in which the data to be deconvolved consist of sensor array measurements. The aim is to find the original source signal (wavelet) and signature of the medium (reflectivity sequence) from the available sensor measurements. Our model assumes that the data are generated as a convolution of an unknown wavelet with various time-scaled versions of an unknown reflectivity sequence. This type of data occurs in many array signal processing applications, including radar, sonar and seismic processing. Our approach relies on exploiting the redundancy in the measurements due to time-scaling which is introduced by the geometry and the sensor placement, and does not require knowledge of the wavelet or reflectivity sequence. Furthermore, we make no assumptions on the statistical properties of these signals. We formulate and solve the deconvolution problem as a quadratic minimization subject to a quadratic constraint. We also illustrate the performance of the technique using simulation examples. © 1997 Elsevier Science B. V

Multiscale deconvolution of sensor array signals via sum-of-cumulants

This correspondence presents a solution to a multiscale deconvolution problem using higher order spectra where the data to be deconvolved consist of noise-corrupted sensor array measurements. We assume that the data are generated as a convolution of an unknown wavelet with reflectivity sequences that are linearly time-scaled versions of an unknown reference reflectivity sequence. This type of data occurs in many signal processing applications, including sonar and seismic processing. Our approach relies on exploiting the redundancy In the measurements due to time scaling and does not require knowledge of the wavelet or the reflectivity sequences. We formulate and solve the deconvolution problem as a quadratic minimization subject to a quadratic constraint in the sum-of-cumulants (SOC) domain. The formulation using the SOC approach reduces the effect of additive Gaussian noise on the accuracy of the results when compared with the standard time-domain formulation. We demonstrate this improvement using a simulation example. © 1997 IEEE

Measures of depression in Alzheimer’s disease

Depression impacts a large number of patients with dementia and Alzheimer’s disease (AD), with several studies reporting between 20% and 60% of AD patients diagnosed with depression (Reichman & Coyne, 1995). Diagnosing depressive disorder in dementia is difficult due to overlap in symptoms, poor communication of symptoms, and lack of insight (Burke, Goldfarb, Bollam, & Khokher, 2019; Dias, Barbosa, Kuang, & Teixeira, 2020). Shared symptoms between depression and dementia include sleep disturbances, changes in eating behavior, decreased initiative and interest (apathy), psychomotor agitation, poor concentration, anxiety, and tearfulness. Depressive symptoms not commonly seen in dementia without depression are consistent sadness, marked morning mood worsening, feelings of worthlessness or excessive or inappropriate guilt, recurrent thoughts of death and suicidal ideation or behaviors

Levels of DNA Adducts in the Blood and Follicular Fluid of Women Undergoing In Vitro Fertilization Treatment and Its Correlation with the Pregnancy Outcome

This study is designed to investigate the impact of DNA damage on pregnancy and fertilization rate outcome in a sub-sample of women undergoing IVF treatment. Blood and follicular fluid samples (n = 60) were analyzed for DNA adducts. While no BPDE-DNA adducts were detected, other unknown lipophilic adducts were seen in blood and follicular fluid. Women who failed to achieve pregnancy had higher DNA adducts in follicular fluid than those who succeeded (p < 0.05). Follicular fluid cotinine levels were associated with DNA adduct levels in blood and follicular fluid (p < 0.05). Evaluation of DNA damage resulting from oxidative stress could have a role in predicting IVF success rate. © 2009 Springer Science+Business Media, LLC

The nature of depression in dementia : a narrative review

Depression is comorbid with various types of dementias (Amore, Tagariello, Laterza, & Savoia, 2007; Baruch, Burgess, Pillai, & Allan, 2019; Kuring, Mathias, & Ward, 2018). Depression is reported to be one of the highest mental health problems occurring in the elderly population and a common symptom of individuals with dementia (Australian Bureau of Statistics, 2015). In most Alzheimer’s disease (AD) patients, depressive symptomatology presents as mild to moderate. Severe forms of depression are less prevalent; 5%-30% of AD patients may be diagnosed with a major depressive episode (Reichman & Coyne, 1995). Depressive symptoms in dementia include apathy, slow movement, dysthymia, or minor and atypical depressive syndromes (Teri & Wagner, 1992). Several studies have shown that depression in AD represents a relapse of preexisting depression in less than 10% of AD patients (Jaroudi et al., 2017). However, for most AD patients, the symptoms of depression are developing for the first time

Mindfulness and meditation : treating cognitive impairment and reducing stress in dementia

This study investigates the relationship between mindfulness, meditation, cognition and stress in people with Alzheimer's disease (AD), dementia, mild cognitive impairment and subjective cognitive decline. Accordingly, we explore how the use of meditation as a behavioural intervention can reduce stress and enhance cognition, which in turn ameliorates some dementia symptoms. A narrative review of the literature was conducted with any studies using meditation as an intervention for dementia or dementia-related memory conditions meeting inclusion criteria. Studies where moving meditation was the main intervention were excluded due to the possible confounding of exercise. Ten papers were identified and reviewed. There was a broad use of measures across all studies, with cognitive assessment, quality of life and perceived stress being the most common. Three studies used functional magnetic resonance imaging to measure functional changes to brain regions during meditation. The interventions fell into the following three categories: mindfulness, most commonly mindfulness-based stress reduction (six studies); Kirtan Kriya meditation (three studies); and mindfulness-based Alzheimer's stimulation (one study). Three of these studies were randomised controlled trials. All studies reported significant findings or trends towards significance in a broad range of measures, including a reduction of cognitive decline, reduction in perceived stress, increase in quality of life, as well as increases in functional connectivity, percent volume brain change and cerebral blood flow in areas of the cortex. Limitations and directions for future studies on meditation-based treatment for AD and stress management are suggested