Age-dependent chlorpyrifos (CPF) metabolism was quantified by in vitro product formation in human hepatic microsomes (ages 13 d-75 y) and plasma (ages 3 d-43 y) with gas chromatography/mass spectrometry (GC/MS). Hepatic CPF cytochrome P450 (CYP) desulfuration (CPF to chlorpyrifos-oxon [CPF-oxon]) and dearylation (CPF to 3,5,6-trichloro-2-pyridinol [TCPy]) V(max) values were 0.35 ...

Adult hippocampal neurogenesis contributes to the hippocampal circuit's role in cognitive functioning. New neurons are generated from hippocampal neural stem cells (NSCs) throughout life, but their generation is substantially diminished in aged animals due to a decrease in NSC proliferation. Because acetylcholine (ACh) is an important neurotransmitter released in the ...

Mark, 54 years of age, has a nontender lump on his praecordium that has been present 'for a long time'. He vaguely recalls a smaller lump at the same site years ago, which he squeezed, with subsequent resolution. Mark denies any bleeding, however, he has noticed occasional yellowish-brown stains on ...

Many factors, such as nitric oxide synthase, androgen and growth factors, can regulate the tone of corpus cavernosum (CC) smooth muscle with an age-related tendency. It has been shown that the active metabolites of kallikreins-kinins system (KKS), including bradykinin, Lys-BK and Met-Lys-BK, can also relax the CC smooth muscle significantly ...

This study uses a new source of linked census data (N = 6,734) to test theories proposed to explain the high intergenerational coresidence in 19th-century America. Was it a system of support for dependent elderly, or did it reflect intergenerational interdependence? I focus on transitions from middle age to old ...

Palerasnitsynus ohlhoffigen. et sp. n. is described fromBurmese amber of late Albian (Lower Cretaceous) age. This is the first record of the family Psychomyiidae from Burmese amber, and the earliest fossil record of the family. The genus Palerasnitsynusgen. n. differs from all other known psychomyiid genera by the absence of ...

Male genital mutilation is a common mechanism by which males reduce sperm competition by plugging female insemination ducts with different parts of its own genital system. This behavior is frequent in many spider families but is uncommon in Haplogynae. The reproductive biology of Dysderoidea is not well studied and the ...

To analyze gender differences in cleft pattern by the clinical statistical study of Japanese patients with cleft lip and/or cleft palate. Cleft pattern modeling was used to analyze 782 patients with cleft lip and/or cleft palate (417 males and 365 females) who had been examined at the Cleft Lip and ...

The ovarian steroid hormones estradiol and progesterone regulate a wide variety of non-reproductive functions in the central nervous system by interacting with molecular and cellular processes. A growing literature from studies using rodent models suggests that 17β-estradiol, the most potent of the biologically relevant estrogens, enhances synaptic transmission and the ...

In our study we investigated the influence of dopamine (DA) on the caudal photoreceptor (CPR) in crayfish. Here we report the following: (a) the chromatographic determination of DA in the sixth abdominal ganglion (6th AG) shows a variation in the content during a 24-h cycle with the maximum value at ...

Aging is the single most significant risk factor for erectile dysfunction (ED), leading to structural modification of cavernous tissue and altering expression of vascular growth factors. The angiopoietin/Tie2 system has been recently considered as a potential target for therapy of vascular disorders, including ED. Hence, the aim of this study ...

The effects of immobilization (1 h/day) of female rats from days 15 to 18 of pregnancy on the secretion of sex steroid hormones depending on the stage of the estrous cycle, functional activity of the hypophyseal-adrenocortical system (HAS), and its sensitivity to regulatory signals were studied in their female offspring ...

Ribosomal protein S3 (rpS3) is well known to participate in DNA repair mechanisms. In the present study, we compared rpS3 immunoreactivity and its protein levels in the hippocampus among young, adult and aged gerbils. In the postnatal month (PM) 3 group as the young, rpS3 immunoreaction was observed in pyramidal ...

The change with age in pain perception in humans and the nociceptive behaviors in animals elicited by noxious stimuli to the skin are not well understood, and little is known about the peripheral neural mechanisms of cutaneous nociception in the aged. We systematically examined cutaneous nociceptor responses and nociceptive behaviors ...

Changes of the anorexigenic and hypermetabolic components of the overall catabolic effect of alpha-MSH were studied in rats as a function of age. In male Wistar rats a 7 day-long intracerebroventricular infusion of alpha-MSH suppressed food intake and caused a fall in body weight in 2 and 3-4 month-old (young) ...

Paranodal axo-glial junctional complexes anchor the myelin sheath to the axon and breakdown of these complexes presumably facilitates demyelination. Myelin deterioration is also prominent in the aging central nervous system (CNS); however, the stability of the paranodal complexes in the aged CNS has not been examined. Here, we show that ...

An age-related proinflammatory, pro-oxidant state in the nigra may increase the vulnerability of dopaminergic neurons to additional damage. Angiotensin II, via type 1 (AT1) receptors, is one of the most important known inflammation and oxidative stress inducers. However, it is not known if there are age-related changes in the nigral ...

Clinical findings reveal that middle-aged patients are more susceptible to suffer from psychiatric disorders than older ones. However, little is known about the emotional behavior of aging rodents. This study aimed to investigate behavioral alterations in male middle-aged Wistar rats in the open-field (OF) test (at illuminated and dimly light ...

Normal aging is associated with impairments in stimulus recognition. In the current investigation, object recognition was tested in adult and aged rats with the standard spontaneous object recognition (SOR) task or two variants of this task. On the standard SOR task, adult rats showed an exploratory preference for the novel ...

Aging increases the risk of both erectile dysfunction (ED) and cardiovascular disease. These conditions have similar etiologies and commonly coexist. One unifying concept is the role of arterial insufficiency which is a primary factor in the onset of age-related ED. Based on the novel finding that the pudendal arteries contribute ...

Estradiol (E) mediates increased synaptogenesis in the hippocampal CA1 stratum radiatum (sr) and enhances memory in young and some aged female rats, depending on dose and age. Young female rats express more estrogen receptor α (ERα) immunolabeling in CA1sr spine synapse complexes than aged rats and ERα regulation is E ...

Biologic scaffold materials composed of mammalian extracellular matrix (ECM) are commonly used for the repair and reconstruction of injured tissues. An important, but unexplored variable of biologic scaffolds is the age of the animal from which the ECM is prepared. The objective of the present study was to compare the ...

Function of visual cortical cells declines during normal aging. Whether there are sex-related differences in this functional degradation is still unknown. In the present study we compared the properties of adaptation, onset latency, and signal-to-noise ratio of visual cortical cells between age-matched sexes in order to investigate any sex related ...

The first purpose of this study was to determine the effect of advanced age (31 months) on the number of motoneurons in the lumbar enlargement of the rat and to determine if motoneurons die via apoptosis with age. The second purpose was to determine if caloric restriction (CR) would attenuate ...

It is largely accepted that neurogenesis in the adult brain decreases with age and reduced levels of local neurotrophic support is speculated to be a contributing factor. Among neurotrophic factors involved on neurogenesis, we focused our attention on the neurotrophic system fibroblast growth factor-2 (FGF-2) and its receptor FGFR1, a ...

Caloric restriction (CR) is a reduction of total caloric intake without a decrease in micronutrients or a disproportionate reduction of any one dietary component. While CR attenuates age-related cognitive deficits in tasks of hippocampal-dependent memory, the cellular mechanisms by which CR improves this cognitive decline are poorly understood. Previously, we ...

A decrease in the excitability of CA1 pyramidal neurons contributes to the age related decrease in hippocampal function and memory decline. Decreased neuronal excitability in aged neurons can be observed as an increase in the Ca(2+)- activated K(+)- mediated post burst afterhyperpolarization (AHP). In this study, we demonstrate that the ...

Circulating estrogen levels and hippocampal-dependent cognitive functions decline with aging. Moreover, the responses of hippocampal synaptic structure to estrogens differ between aged and young rats. We recently reported that estrogens increase levels of post-synaptic proteins, including PSD-95, and opioid peptides leu-enkephalin and dynorphin in the hippocampus of young animals. However, ...

We employed environmental tracers ((3)H-(3)He, SF(6)) in a study investigating the groundwater recharge in the North China Plain (NCP), a sedimentary aquifer system consisting of fluvial and alluvial river deposits near the city of Shijiazhuang. The (3)H-(3)He dating method revealed reasonable results for the young groundwater with ages covering the ...

Hair follicle and fibre characteristics of Peruvian alpaca and llama and Bolivian llama were analysed in three experimental studies. The first experiment was designed to determine the age at which all the secondary follicles reach maturity, as well as to compare the skin follicular structure and activity among these different ...

Aging changes in the stomach lead to a decreased capacity for tissue repair in response to gastric acid. The aim of this study was to determine the mechanism associated with the increased susceptibility to injury of aging mucosa including reactive oxygen species (5), apoptosis, angiogenesis, and sensory neuron activity. Fischer ...

Aging is inevitably accompanied by gradual and irreversible innate endothelial dysfunction. In this study, we tested the hypothesis that accentuation of glucose metabolism via the aldose reductase (AR) pathway contributes to age-related vascular dysfunction. AR protein and activity levels were significantly increased in aged vs. young aortic homogenates from Fischer ...

Epilepsy is known to influence hippocampal dentate granule cell (DGC) layer neurogenesis. In young adult rats, status epilepticus (SE) increases the number DGC newly borne cells and basal dendrites (BD), which persist at long-term. In contrast, little is known on whether these phenomena occur in elderly epileptic animals. In the ...

Little is known about how normal aging affects the brain. Recent evidence suggests that neuronal loss is not ubiquitous in aging neocortex. Instead, subtle and still controversial, region- and layer-specific alterations of neuron morphology and synapses are reported during aging, leading to the notion that discrete changes in neural circuitry ...

This study aims to determine whether the regulation of extracellular glutamate is altered during aging and its possible consequences on synaptic transmission and plasticity. A decrease in the expression of the glial glutamate transporters GLAST and GLT-1 and reduced glutamate uptake occur in the aged (24-27 months) Sprague-Dawley rat hippocampus. ...

Studies completed in human subjects have made seminal contributions to understanding the effects of age on sympathetic nervous system (SNS) regulation. Numerous experimental constraints limit the design of studies involving human subjects; therefore, completion of studies in animal models of aging would be expected to provide additional insight regarding mechanisms ...

Cognitive decline is a virtually universal aspect of the aging process. However, its neurophysiological basis remains poorly understood. We describe here more than 20 age-related cortical processing deficits in the primary auditory cortex of aging versus young rats that appear to be strongly contributed to by altered cortical inhibition. Consistent ...

Aging, which is an independent risk factor for heart disease, alters body fat mass and its function. Epicardial fat plays an important physiological and pathophysiological role on cardiac structure and function. This study investigated if aging altered the abundance of epicardial (EF) and abdominal fat (AF) derived mediators in a ...

Our previous studies have shown that both apoptosis and necrosis are involved in hair cell (HC) pathogenesis in aging cochleae. To better understand the biological mechanisms responsible for the regulation of HC death, we examined the activity of succinate dehydrogenase (SDH), a mitochondrial bioenergetic enzyme, in the HCs of aging ...

Epidemiological studies have revealed a strong genetic contribution to the risk for depression. Both reduced hippocampal serotonin neurotransmission and brain-derived neurotrophic factor (BDNF) levels have been associated with increased depression vulnerability and are also regulated during aging. Brains from young (5 months old) and old (13 months old) congenital Learned ...

Aging is associated with neurochemical changes in the brain that result in impaired vestibular reflex function. We analysed the concentrations of 9 related neurochemicals (l-arginine, l-citrulline, l-ornithine, agmatine, putrescine, spermidine, spermine, glutamate and gamma-aminobutyric acid (GABA)) in the vestibular nucleus of aged (24 months old) and young (4 month old) ...

The process of aging is linked to oxidative stress, microglial activation, and proinflammatory factors, which are known to decrease cell proliferation and limit neuroplasticity. These factors may lead the transition from normal aging to more severe cognitive dysfunction associated with neurodegenerative diseases. We have shown that natural compounds such as ...

Bacterial lipopolysaccharide (LPS) in rodents is an established model for studying innate immune responses to gram-negative bacteria and mimicking symptoms of infections including reduced food intake associated with decreased circulating total ghrelin levels. The ghrelin-acylating enzyme, ghrelin-O-acyltransferase (GOAT) involved in the formation of acyl ghrelin (AG) was recently identified. We ...

Degeneration of the cholinergic neurons in the basal forebrain and elevation of inflammatory markers are well-established hallmarks of Alzheimer's disease; however, the interplay of these processes in normal aging is not extensively studied. Consequently, we conducted a neuroanatomical investigation to quantify cholinergic neurons and activated microglia in the medial septum/vertical ...

Age is characterized by deficits in synaptic function identified by decreased performance of aged animals in spatial learning tasks and reduced ability of animals to sustain long term potentiation (LTP). Several cellular and molecular events are correlated with these deficits, many of which are indicative of age-related neuroinflammatory and oxidative ...

Circulating levels of endothelin (ET)-1 and endogenous ET(A)-mediated constriction are increased in human aging. The mechanisms responsible are not known. Investigate the storage, release, and activity of ET-1 system in arteries from young and aged Fischer-344 rats. After NO synthase inhibition (L-NAME), thrombin contracted aged arteries, which was inhibited by ...

Maintenance of normal glucose homeostasis is crucial for survival during the perinatal period. Acylated ghrelin (AG) but not unacylated ghrelin (UAG) inhibits insulin release from pancreatic islets in adult rats. Circulating AG concentrations are low in the fetus and progressively increase in the postnatal period. We tested the hypothesis that ...

The total number of hippocampal pyramidal cells in the CA2-CA3 region are reported to be unaffected by undernutrition during the gestation period. We hypothesised that this may not be the case in animals subjected to a lengthier period of undernutrition. Wistar rats were undernourished from conception until 21 post-natal days-of-age ...

Onchocerciasis is endemic in the Imo River Basin, Nigeria. This study was aimed at assessing the prevalence and intensity of microfilaria of Onchocerca volvulus in the area. A cross-sectional study was carried out in the Okigwe Local Government Area, Imo State, Nigeria. Two skin snips (one from the waist and ...

Dysregulation of the cholinergic transmitter system is a hallmark of Alzheimer's disease and contributes to an age-associated decline in memory performance. The current study examined the influence of carbachol, a cholinergic receptor agonist, on synaptic transmission over the course of aging. Extracellular excitatory postsynaptic field potentials were recorded from CA3-CA1 ...