Influence of fat intake and caloric restriction on bone in aging male rats

Caloric and fat intake may have important skeletal consequences. To evaluate this possibility, skeletal effects of adult-onset caloric restriction (CR) at differing fat intakes were assessed in male Lobund-Wistar rats. At age 17 months, two groups of animals received an anti-obesity diet, restricted approximately 35% from individual ad libitum baseline calorie consumption, and two groups received a diet approximately 50% restricted. Dietary fat concentrations were 5, 15, 15, and 25% by weight, respectively. At ages 20, 24, 28, 30, and 32 months, ex vivo femoral bone densitometry and serum biochemical analyses were performed. Body weight (BW) decreased with time on CR in each group (p < .005), declining faster at the more severe restriction (p = .001). Femoral bone mineral contents (BMC) were also reduced. After adjusting for bone area and BW differences among groups, the only significant difference was a reduction in distal femur BMC in the 25% fat group subjected to more severe CR (p = .02). No differences were observed in serum parathyroid hormone, calcium, phosphorus, or creatinine. Femoral bone loss occurred with CR. This was entirely accounted for by reduction in BW. Higher dietary fat content did not affect BW in CR animals, but did result in lower distal femur BMC.     

Palatability and foraging cost interact to control caloric intake.

The combined effects of meal cost and food flavor on meal size were studied with a method that avoided the covariation of nutrient composition and caloric density with palatability. As rats (Rattus norvegicus) drank flavored fluids (unpalatable 0.05% sucrose octaacetate [SOA], neutral 0.05% saccharin, and palatable 2% Polycose?+?0.2% saccharin [P?+?S]), liquid diet was infused intragastrically. Relative to saccharin, rats with free access ate 10% more calories in larger meals while consuming P?+?S and initially ate fewer calories in smaller but more frequent meals while drinking SOA. Other rats lever-pressed to begin meals, which halved meal number and doubled meal size relative to the free-access group. Although foraging rats also ate larger P?+?S meals and smaller SOA meals, the changes did not affect total intake. Without the usual differential postingestive effects of foods that differ in palatability, making food more costly blunts rats' response to its flavor. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of aging on cortical and trabecular bone response to estradiol treatment in ovariectomized rats

Three groups (n = 15/group) of 6-, 12- and 30-month-old (mature, old and senescent animals, respectively) female Wistar rats on a diet (6 g/100 g BW/ day) containing 0.8% calcium and 0.8% inorganic phosphorus were studied. Within each group, 10 rats were ovariectomized surgically and 5 injected s.c. with 17 beta-estradiol (E rats, 10 micrograms/kg BW/48 h) and 5 with solvent alone (OVX rats) from day 2 until day 60 after ovariectomy. Five other rats were sham-operated (SH rats) and received solvent only. All rats were killed by exsanguination 60 days after ovariectomy. Neither ovariectomy nor estradiol treatment had a significant effect upon tibial mechanical properties in 6-, 12- and 30-month-old animals. Bone mineral density (BMD) and bone mineral content (BMC) of the distal femur and BMC of the whole femur were decreased by ovariectomy in 6- and 12-month-old rats, but were not different in the SH and E groups. In senescent animals, in which the lowest BMD and BMC were measured, estradiol treatment was more effective in increasing these parameters than in adult and old rats. Image analysis of the distal femoral diaphysis showed that estradiol treatment prevented trabecular bone loss induced by senescence and/or ovariectomy. In each group, urinary deoxypyridinoline excretion and plasma osteocalcin concentration were higher in the OVX animals than in the controls, consistent with increased bone turnover in the estrogen-deficient state. Both biochemical turnover markers were reduced in the estrogen-treated groups. These results indicate that 17 beta-estradiol is particularly effective at preventing high-turnover-induced osteopenia in 30-month-old animals.     

Relaxation training and cardiovascular response to experimental stressors.

Blood pressure (BP) and heart rate were measured in 36 Ss (mean age 33 yrs) during periods of rest, intentional relaxation, unsignaled reaction time (RT), cold pressor tasks, and recovery periods, both before and after 4 wks of progressive relaxation training, transcendental meditation analog treatment, or an assessment control condition. Both types of relaxation training resulted in significant reductions in BP, but not heart rate, levels across all posttreatment assessment intervals (baseline, stress periods, and stress recovery). Relaxation training did not reduce cardiovascular response during stress periods, but did result in more rapid BP reductions in stress recovery periods. Scores on the Jenkins Activity Survey were related to posttreatment BP level during the RT task, with high scorers showing higher BPs than low scorers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Daily caloric intake in intact and chronic decerebrate rats.

Daily caloric intake regulation was studied in chronic supracollicular decerebrate rats with a complete transaction of the neural axis at the meso–diencephalic juncture and in intact controls. For 1 wk, each rat received 3 intraorally delivered meals per day. They were challenged to maintain their 3-meal daily intake over 1 wk, in which only 2 meals per day were delivered. Intact rats increased meal size to compensate for the lost opportunity to feed, whereas chronic decerebrate rats did not. Results suggest that, although the caudal brain stem, as previously shown (H. J. Grill and J. M. Kaplan, 1990), is sufficient to modulate ingestive behavior in taste reactivity and single-meal tests, it is not sufficient to regulate daily caloric intake. Although it is possible that chronic decerebrate rats retain a long-term regulatory competence that is somehow masked under the meal omission paradigm, forebrain–hindbrain interactions appear necessary for the coordination of short- and long-term control processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impedance cardiography used to assess patterns of cardiovascular response to behavioral stressors

This paper presents two examples of how impedance cardiography may be used to interpret the hemodynamic influences on blood pressures measured during behavioral stress. In Study 1, blood pressure changes which were similar during two tasks were shown to have important differences in their cardiac output and vascular resistance components. During work on a reaction time task having aversive incentives compared with a neutral task, the blood pressure changes were seen to be associated with lowered vascular resistance and raised cardiac activity, a "fight-flight" pattern. In Study 2, blood pressure response differences between two subject groups working on an identical task were found to have blood pressure changes differing in their underlying cardiac and vascular components as measured by impedance. Such uses impedance cardiography have widespread potential application in psychophysiological research with humans.     

Normal aging dampens the link between intrusive thoughts and negative affect in reaction to daily stressors.

We charted daily variations in intrusive thoughts to gain access to adult age differences in affective reactivity to daily stressors. On 100 days, 101 younger and 103 older adults reported stressors, intrusive thoughts, and negative affect. Although increments in intrusive thoughts were similar in both age groups on days with stressors, older adults' negative affect increased less than younger adults' on such days. In addition, (a) levels of intrusive thoughts and negative affect across study time were positively associated; (b) days with increased thoughts were days with increased negative affect; and (c) experiencing above-average intrusive thoughts about stressors strengthened affective reactions to stress. Relative to younger adults, all three associations were reduced in older adults. We tentatively conclude that normal aging dampens the stress-induced link between intrusive thoughts and affect. This dampening may contribute to preserved affective well-being and reduced affective reactivity to daily stress in old age. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Mouse model of fragile X syndrome: Behavioral and hormonal response to stressors.

Fragile X syndrome, a form of mental retardation caused by inadequate levels of fragile X mental retardation protein (FMRP), is characterized by extreme sensitivity to sensory stimuli and increased behavioral and hormonal reactivity to stressors. Fmr1 knockout mice lack FMRP and exhibit abnormal responses to auditory stimuli. This study sought to determine whether Fmr1 knockout mice on an F1 hybrid background are normal in their response to footshock. Knockout mice were also examined for signs of hyperexcitation across an extended trial range, and serum corticosterone levels were evaluated in response to various stressors. The ability to acquire conditioned taste aversion was also assessed. Knockout mice exhibited no impairment in associative aversive learning or memory, since they successfully expressed conditioned taste aversion. Footshock-sensitivity, freezing behavior, and corticosterone response to various stressors did not differ between knockout and wild-type mice. However, knockout mice exhibited significantly increased responses during the extended test. The knockout mice’s increased responsiveness to footshock in the extended test may be an indication of increased vulnerability to stress or enhanced emotional reactivity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of aging on the pharmacokinetics and pharmacodynamics of doxacurium

OBJECTIVE: Different sets of diagnostic criteria have been proposed for Sj?gren's syndrome (SS), but none have been validated with a large series of patients or in a multicenter study. We conducted the present study involving 26 centers from 12 countries (11 in Europe, plus Israel), with the goals of reaching a consensus on the diagnostic procedures for SS and defining classification criteria to be used in epidemiologic surveys and adopted by the scientific community. METHODS: The study protocol was subdivided into two parts. For part I, questionnaires regarding both ocular and oral involvement were developed; they included 13 questions and 7 questions, respectively. For part II a limited set of diagnostic tests was selected, and the exact procedure to be followed in performing these tests was defined. Part I of the study included 240 patients with primary SS and 240 age- and sex-matched controls. Two hundred forty-six patients with primary SS, 201 with secondary SS, 113 with connective tissue diseases but without associated SS, and 133 control patients were studied in part II. RESULTS: The study resulted in (a) the validation of a simple 6-item questionnaire for determination of dry eyes and dry mouth, which showed good discriminant power between patients and controls, to be used in the initial screening for sicca syndrome; and (b) the definition of a new set of criteria for the classification of SS. The sensitivity and specificity of the criteria in correctly identifying patients with either the primary or the secondary variant of SS were also determined. CONCLUSION: Using the findings of this prospective multicenter European study, general agreement can be reached on the diagnostic procedures to be used for patients with SS. Final validation of the preliminary classification criteria for SS is underway.     

Effects of goal-setting and of goal levels on weight loss induced by self-monitoring of caloric intake.

The daily caloric intake of 53 18–45 yr old Ss was monitored. A caloric intake monitoring (CIM)-no-goal group was compared with CIM–low-goal group, a CIM–moderate-goal group, and a CIM–high-goal group. While CIM combined with goal-setting produced more weight loss than CIM combined with no goal, various levels of goal did not differentially affect weight loss over a 4-wk period. (French abstract) (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of aging on arterial compliance

We present a case of neuropsychiatric lupus erythematosus with granular calcification in the basal ganglia and cerebral white matter on CT. Histopathologically, these were identified as perivenous necrotising lesions, with loss of axons and myelin sheaths and prominent dystrophic calcification.     

Influence of stressors on breast cancer incidence in the Women's Health Initiative.

Objective: To examine associations among life events stress, social support, and breast cancer incidence in a cohort of postmenopausal women. Design and main outcome measure: Women's Health Initiative observational study participants, breast cancer free at entry, who provided assessment of stressful life events, social support, and breast cancer risk factors, were prospectively followed for breast cancer incidence (n = 84,334). Results: During an average of 7.6 years of follow-up, 2,481 invasive breast cancers were diagnosed. In age-adjusted proportional hazards models, 1 stressful life event was associated with increased risk, but risk decreased with each additional stressful life event. After adjustment for confounders the decreasing risk was not significant. Stressful life events and social support appeared to interact in relation to breast cancer risk such that women who had greater number of stressful life events and low social support had a decreased risk of breast cancer. Conclusions: This study found no independent association between stressful life events and breast cancer risk. The results are compatible with a more complex model of psychosocial factors interacting in relation to breast cancer risk. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The physiologic, neurologic, and behavioral effects of caloric restriction related to aging, disease, and environmental factors

Little is known about the mechanisms by which acute and chronic caloric restriction (CR) modulate disease, longevity, and toxicity. To study these endpoints, behavioral parameters such as food and water consumption and physiologic parameters such as motor activity, body temperature, metabolic output (oxygen use), and respiratory quotient (RQ) were continuously monitored in 26-month-old male B6C3F1 mice and Fischer 344 rats fed either ad libitum (AL) or a CR diet (60% of AL). Different dietary regimens were used: rodents were (1) chronically food-restricted using daily feeding starting at 14 months of age, (2) chronically food-restricted using alternate day feeding, or (3) abruptly switched from CR to AL (acute CR). The physiologic and behavioral changes seen with chronic and acute CR were consistent across strains and species. Average body temperature, the number of meals, and the ratio of food/water consumption were significantly lower in CR rodents than in AL rodents. Also, the daily range of body temperature, oxygen metabolism, RQ, average water consumption, and motor activity was significantly higher in CR rodents. CR caused the onset of altered neurobehavioral functions such as abnormal water consumption; increases in motor activity, serum corticosterone, and stress proteins (HSP); and decreases in the basal setpoint for body temperature and brain metabolism. These changes strongly suggest that many beneficial effects of CR are controlled by the hypothalamic-pituitary-adrenal axis via hormonal regulation. This study supports the assertion that nutritional status may be a primary factor of consideration in development of safety standards and assessment of risk.     

Influence of mode and carbohydrate on the cytokine response to heavy exertion

1. This experiment was carried out to evaluate the productive and physiological consequences of a slight but long term food restriction of male broiler chickens from 2 commercial strains. 2. Cobb-500 and Ross chickens were submitted to a 20% food restriction from 8 to 21 d of age. Strain, food programme and their interactive effects were analysed in terms of consequences upon performance, mortality, incidence of sudden death syndrome (SDS) and ascites syndrome (AS), index of right cardiac hypertrophy and plasma concentrations of hormones related to metabolism and growth (T3, T4, T3:T4 ratio, IGF-I and GH). 3. Although some catch-up growth was observed by refeeding previously restricted birds after 22 d of rearing, food restriction decreased (P < or = 0.05) body weight at market age (42 d) irrespective of the strain, but improved (P < or = 0.05) food conversion. 4. The incidence of mortality was not high in non-restricted birds but SDS and AS caused more than 50% of deaths. Hypertrophic cardiac index was observed in chickens of both strains after 4 weeks of age and was higher in ad libitum fed birds. 5. During the period of food restriction, plasma T3 and IGF-I concentrations decreased whereas plasma T4 and GH concentrations increased compared to those of the age-matched ad libitum fed counterparts. During the subsequent ad libitum feeding period, few differences in circulating hormone concentrations were observed, except for the higher mean GH litres in previously food-restricted chickens at 35 d of age. 6. These results indicate that even a non-severe food restriction negatively affects body weight of 42-d-old male broilers but these are benefits with improved food efficiency and diminished mortality from metabolic disturbances. The hormone results suggest that the degree of food restriction applied was not severe because there was a very fast adaptive response with small and transient alterations in T3, T4 and GH plasma concentrations during the period of compensatory growth.     

Correlation between the age-dependent changes in caloric response and in pure tone hearing

Function and biochemical properties of the V2 vasopressin receptor (V2R) mutant R337ter, identified in patients suffering from X-linked recessive nephrogenic diabetes insipidus, were investigated by expression in COS.M6 or HEK293 cells. Binding assays and measurements of adenylyl cyclase activity failed to detect function for the truncated receptor, although metabolic labeling demonstrated normal levels of protein synthesis. ELISA assays performed on cells expressing the receptors tagged at the amino terminus with the HA epitope failed to detect V2R R337ter on the plasma membrane. Treatment with endoglycosidase H revealed that the receptor was present only as a precursor form because the mature R337ter V2R, resistant to endoglycosidase H treatment, was not detected. The precursor of V2R-R337ter had a longer half-life than that of the wild type V2R, suggesting that arrested maturation may slow the degradation of the precursor. Unrelated experiments had demonstrated that V2R-G345ter, containing eight additional amino acids, was expressed on the plasma membrane and functioned normally. Receptor truncations longer than 337ter revealed that four of the eight amino acids identified initially provided the minimum length required for the protein to acquire cell surface expression. This was shown by the production of mature receptor (V2R-341ter) detectable in SDS-PAGE, which mediated arginine vasopressin stimulation of adenylyl cyclase activity and bound ligand. In addition, the identity of amino acid 340 was found to play a role in this phenomenon. In conclusion, these data demonstrate that the V2R R337ter is nonfunctional because it does not reach the plasma membrane and that the minimal protein length required for translocation of the V2R to the cell surface is sufficient to confer function to the receptor protein. They also suggest the existence of a protein quality control in the endoplasmic reticulum independent of glycosylation.     

Reproducibility of the response to short-term low salt intake in essential hypertension

If an ultrasound probe comes close to the area of interest, high ultrasound frequencies can be applied. Endoscopic ultrasonography is performed by means of echoendoscopes or miniature probes using ultrasound frequencies between 7 and 30 MHz. A high frequency ultrasound image of the normal gastrointestinal wall usually shows five layers corresponding closely to the histological layers of the wall. Corrections have to be made, however, for interface echoes between layers with different acoustic impedances. We describe studies performed with the aim of correlating ultrasound images of the normal and diseased gastrointestinal wall with the histology. Ultrasound images of the normal gastrointestinal wall and pathological changes like ischemia, ulcers, tumours and inflammation are presented.     

A study of caloric restriction and cardiovascular aging in cynomolgus monkeys (Macaca fascicularis): a potential model for aging research

Caloric restriction has been demonstrated to retard aging processes and extend maximal life span in rodents, and is currently being evaluated in several nonhuman primate trials. We initiated a study in 32 adult cynomolgus monkeys to evaluate the effect of caloric restriction on parameters contributing to atherosclerosis extent. Following pretrial determinations, at which time a baseline measure of ad libitum (ad lib) dietary intake was assessed, animals were randomized to an ad lib fed group (control) or a caloric restriction group (30% reduction from baseline intake). The animals are being evaluated for glycated proteins, insulin, glucose, insulin sensitivity measures, and specific measures of body fat composition by CT scans (e.g., intra-abdominal fat) over specified intervals. The results from the first year of observation demonstrate a significant diet effect on body weight, and specifically intra-abdominal fat. Further, insulin sensitivity has been significantly increased after 1 year of caloric restriction compared to the ad lib fed group. These studies indicate that caloric restriction has a marked effect on a pathologic fat depot, and this change is associated significantly with an improvement in peripheral tissue insulin sensitivity.     

On the influence of Si-Ge additions on the aging response of Al-Cu

Al-Cu-Si-Ge alloys display a unique combination of ultrarapid aging response, high peak hardness, and extended-aging microstructural stability. The purpose of this work is to explain these properties in terms of the role that the Si-Ge additions have on modifying the conventional Al-Cu aging sequence. In both AlCu and AlCuSiGe, the room-temperature microstructure consists of both Guinier-Preston (GP) zones and ϑ″ precipitates. Upon aging at 190 °C, Al-Cu displays the well-known precipitation sequence: the slow dissolution of GP zones and ϑ″ and the gradual formation of ϑ′. In the quaternary alloy, Si-Ge particles quickly nucleate and grow during elevated-temperature aging (they are detected after as little as 30 minutes at 190 °C). The Si-Ge particles then act as nucleation sites for ϑ′ precipitates, resulting in a peak-aged microstructure consisting of a dense distribution of ϑ′ attached to Si-Ge.     

Influence of food intake on the absorption of diftalone in man

An average 2.2-fold increase in the peak plasma concentrations of the non-steroidal anti-inflammatory agent diftalone in the presence of food was observed in three studies carried out with healthy volunteers who received an oral dose of 0.75 g (6 subjects, study 1), 0.25 g (10 subjects, study II) and 0.5 g (6 subjects, study V) of the compound at 9:00 a.m. both in fasting conditions and after a meal. The effect does not depend on the unusual time (8:00 a.m., selected for experimental needs) at which the subjects were given the meal. In fact, a 2.5-fold increase in plasma concentrations was observed when an oral dose of 0.75 g of diftalone was administered to 2 subjects (study II) both at 8:00 a.m. in fasting conditions and at 1:00 p.m. after a meal. A similar enhancement in the absorption of diftalone was observed when 5 healthy volunteers (study VI) received an oral dose of 0.5 g of the compound both as plain capsules and as capsules containing dry ox bile. However, the absorption of diftalone was not modified when the compound was administered orally as an aqueous suspension or in tensioactive vehicles, or after 20 mg of metoclopramide (study II). Also, the results of a study (IV) on 2 subjects partly deprived of bile after surgery, showed that diftalone does not undergo enterohepatic circulation. The hypothesis that the increase in diftalone absorption is mainly due to bile flow following food intake is supported by all the above experimental results.