Effect of decreasing dietary phosphorus supply on net recycling of inorganic phosphate in lactating dairy cows.

Five ruminally cannulated lactating Holstein cows, fitted with permanent indwelling catheters in the mesenteric vein, hepatic vein, portal vein, and an artery were used to study intestinal absorption and net recycling of inorganic phosphate (P(i)) to the gastrointestinal tract. Treatments were low P (LP; 2.4 g of P/kg of DM) and high P (HP; 3.4 g of P/kg of DM). The dietary total P (tP) concentrations were obtained by replacing 0.50% calcium carbonate in the LP diet with 0.50% monocalcium phosphate in the HP diet. Diets were fed for 14 d and cows were sampled on d 14 in each period. Cows were fed restrictively, resulting in equal dry matter intakes as well as milk, fat, and protein yields between treatments. Net P(i) recycling (primarily salivary) was estimated as the difference between net portal plasma flux (net absorption of P(i)) and apparently digested tP (feed - fecal tP difference). Phosphorus intake, apparently digested tP, and fecal tP excretion decreased with LP. An effect of decreased tP intake on net portal plasma flux of P(i) could not be detected. However, despite numerically minute net fluxes across the liver, the net splanchnic flux of P(i) was less in LP compared with that in HP. Though arterial plasma P(i) concentration decreased, net P(i) recycling was not decreased when tP intake was decreased, and recycling of P(i) was maintained at the expense of deposition of P(i) in bones. Data are not consistent with salivary P(i) secretion being the primary regulator of P(i) homeostasis at low tP intakes. On the contrary, maintaining salivary P(i) recycling at low tP intakes indicates that rumen function was prioritized at the expense of bone P reserves.

Biomechanical determinants of maximal stair climbing capacity in healthy elderly women.

Stair walking is an important functional movement task that may require considerable amounts of muscle strength/power. This study aimed to perform a descriptive biomechanical analysis of maximal stair ascent in elderly women and to examine the relationship between mechanical muscle function and maximal stair ascending velocity (MAV). Seventeen healthy elderly women (age 72.4 +/- 6.4) were tested for MAV, maximal multi-joint counter movement jumping (CMJ), and maximal single-joint isokinetic/isometric muscle moment. Peak knee joint power during MAV was the single independent parameter that explained most of the variation in MAV (50%), however, combining knee and ankle parameters in a multiple regression analysis mean joint power explained 82.4% of the variation in MAV. Generally, multi-joint CMJ parameters showed stronger correlations with MAV than single-joint isokinetic/isometric muscle strength parameters. MAV appeared to be highly dependent upon knee and ankle power and to a lesser extent on joint moment and range of motion. Furthermore, CMJ assessment seemed well applicable in healthy elderly individuals to distinguish between differentiated levels of maximal stair walking capacity.

Explosive heavy-resistance training in old and very old adults: changes in rapid muscle force, strength and power.

Age-related decline in muscle power predicts falls, motor impairments and disability. Recent guidelines suggested that training programs should be tailored to maximize muscle power. This study investigated the effects of 12 weeks of explosive-type heavy-resistance training (75-80% of 1 repetition maximum) in old (60-65 years, TG60) and very old (80-89 years, TG80) community-dwelling women. Training was performed with maximal intentional acceleration of the training load during the concentric movement phase. Maximal isometric voluntary muscle strength (MVC), rapid force capacity, assessed as rate of force development (RFD), and impulse, maximal muscle power during a countermovement jump (CMJ) and during unilateral leg extension task (LEP) were evaluated. RFD, impulse and MVC increased by 51%, 42% and 28% in TG80, and by 21%, 18% and 18% in TG60, respectively. CMJ jump height increased by 18% and 10% in TG80 and TG60, respectively, while jump peak power increased in TG60 (5%). Finally, LEP increased 28% in TG80 and 12% in TG60. These findings demonstrate that explosive-type heavy-resistance training seems to be safe and well tolerated in healthy women even in the eighth decade of life and elicits adaptive neuromuscular changes in selected physiological variables that are commonly associated with the risk of falls and disability in aged individuals.

Prostatic enlargement, symptomatology and pressure/flow evaluation: interrelations in patients with symptomatic BPH.

INTRODUCTION: Benign prostatic hyperplasia (BPH) is the most common pathologic condition to afflict the aging male. Many patients with symptomatic BPH undergo prostatectomy without rigorous evaluation. Three concepts should be considered before any treatment of a patient with symptomatic BPH; Prostatic enlargement, symptomatology and bladder outflow obstruction. PATIENTS AND METHODS: The study comprised 188 consecutive patients with symptomatic BPH, all eligible after pressure/flow examination. One-hundred-seventy-four of the patients answered the DAN-PSS questionnaire, 140 of the patients had their prostate size measured by transrectal ultrasonography. One-hundred-fifty-three patients were able to perform a free flow measurement upon arrival. Uroflowmetry, symptomatology and prostate size were matched with the results of pressure/flow examination. RESULTS: Neither uroflowmetry, symptomatology nor prostate size correlated well with bladder outlet obstruction. The positive predictive value for infravesical obstruction was 88% if a maximum flow rate under 10 ml/s was used. Symptomatology could not be used to differentiate between patients with bladder outlet obstruction and patients without obstruction. The positive predictive value for infravesical obstruction was 76% if a prostate volume over 40 ml was chosen. DISCUSSION: The purpose of diagnostic evaluation in patients with BPH, is to identify precisely the pathophysiology underlying the patients condition, so that rational therapy can be selected. CONCLUSION: The disease entity of BPH is characterized by the interaction of prostate enlargement, the subjective symptom complex of prostatism, and urodynamic infravesical obstruction. Since it is impossible to interpolate from one to another of these conditions, a comprehensive evaluation of a patient with symptomatic BPH should include an assessment of all of these conditions.

Gastrointestinal development of dairy calves fed low- or high-starch concentrate at two milk allowances.

The objective was to study the effect of type of concentrate with varying starch and fibre content on growth and gastrointestinal development in preweaned dairy calves. Thirty-two newborn Danish Holstein male calves were allocated to four treatment groups in eight blocks of four calves. An experimental low-starch, high-molasses, high-fibre (EXP) concentrate or a traditional high-starch (TRA) concentrate were fed either at a high (HIGH; 2 × 3.2 kg/day) or a low (LOW; 2 × 1.6 kg/day) whole milk allowance in a 2 × 2 factorial design. TRA contained 350 and EXP 107 g starch/kg dry matter (DM), whereas the NDF content was 136 and 296 g/kg DM, respectively. Metabolizable energy (ME) was 11.2 and 12.2 MJ ME/kg DM in EXP and TRA, respectively. All calves had free access to artificially dried grass hay (9.8 MJ ME/kg DM). Four calves were culled during the experiment. The calves were euthanized either at 38 (12 calves) or 56 days (16 calves) of age. Evaluated across both slaughter ages, there was no difference between TRA and EXP in concentrate and hay intake, rumen weight and papillation. EXP resulted in increased villi number in duodenum and jejunum compared with TRA. Concentrate intake and reticulo-rumen weight was higher for LOW compared with HIGH milk allowance, whereas live weight gain was 20% lower. The results show that a low-starch, high-molasses, high-fibre concentrate with 8% lower ME content tended to reduce daily gain compared with a traditional calf starter concentrate, but resulted in similar ruminal development in preweaned calves both on a high and a low milk allowance fed along with grass hay. Furthermore, the results suggest that the experimental concentrate stimulated intestinal villi growth over that of the traditional concentrate.

Effects of gestation and transition diets, piglet birth weight, and fasting time on depletion of glycogen pools in liver and 3 muscles of newborn piglets.

The experiment was conducted to assess the effects of maternal nutrition in late gestation on glycogen pools of newborn piglets of different birth weights and to assess how rapidly the glycogen pools in the liver and 3 muscles are mobilized during fasting. Until d 108 of gestation, 48 sows were fed a gestation standard diet (GSD) with low dietary fiber (DF, 17.1%), or 1 of 3 diets with high DF (32.3 to 40.4%) consisting of pectin residue (GPR), potato pulp (GPP), or sugar-beet pulp (GSP). From d 108 until farrowing, sows were fed 1 of 6 transition diets with low or high dietary fat: one group received a standard diet (TSD; control) containing 3% animal fat, another group received the TSD diet + 2.5 g/d of hydroxy-methyl butyrate as topdressing (THB), and 4 other groups received diets with 8% added fat from coconut oil (TCO), sunflower oil (TSO), fish oil (TFO), or 4% octanoic acid + 4% fish oil (TOA). Two piglets per litter (the second and fifth born) were blood sampled, and 1 was killed immediately after birth, whereas the other, depending on the litter, was killed after 12, 24, or 28.5 to 36 h (mean 32.5 h) of fasting. Samples of liver, LM, M. semimembranousus (SM), and M. diaphragm (DP) were collected and analyzed for glycogen concentration. No dietary effects (P > 0.20) on glycogen concentrations in liver, LM, SM, or DP were observed. The weight of the liver was affected by gestation diet (P < 0.05) and was greater in GSD and GSP piglets (36.7 and 36.3 g) than in GPR piglets (32.6 g), and intermediate (33.6 g) in GPP piglets. Liver weight, estimated muscle mass, and glycogen pools (P < 0.001) were affected by birth weight, whereas glycogen concentrations in liver and LM, SM, and DP muscles were not (P > 0.05). Liver weight; glycogen concentrations in liver, LM, SM, and DP; and glycogen pools in liver and muscles decreased (P < 0.001) with increasing duration of fasting, and at 32.5 h of fasting, glycogen concentration was reduced by 80% in liver, 64% in DP, 46% in SM, and 36% in LM. Based on a broken-line model, labile glycogen in SM, a locomotory muscle, was estimated to be depleted after 16.4 h of fasting. In conclusion, piglet size had a major impact on estimated glycogen pools, whereas sow nutrition in late gestation had a minor impact, if any. Furthermore, varying proportions of pools of glycogen present in liver and selected muscles were mobilized, and data indicate that newborn piglets are fatally depleted of energy after 16 h of fasting.

Exercise on prescription: a randomized study on the effect of counseling vs counseling and supervised exercise.

The aim of this study was to compare short- (0-4 months) and long-term (0-10 months) effects of high-intensive Exercise on Prescription (EoP) intervention (counseling and supervised exercise) implemented in primary healthcare in a number of Danish counties with a low-intensive intervention (counseling) using maximal oxygen uptake (VO(2max)) as the primary outcome. The study was conducted as a randomized trial in 2005-2006 with a high and a low-intensive group. All the patients referred to the EoP scheme by their GP in the counties of Vejle and Ribe, Denmark, were eligible for the trial. The high-intensive EoP group received 4 months of group-based supervised training and attended five motivational counseling sessions. The low-intensive group only attended four motivational counseling sessions. Three hundred and twenty-seven patients entered the EoP scheme, and 52 (16%) volunteered for the randomized trial. No short- or long-term differences were found between the high and the low-intensive groups for VO(2max) (short-term 95% CI -1.1; 4.4 mL O(2)/(kg min), long-term 95% CI -1.6 to 2.1). The present study did not demonstrate any significant clinical outcome for the high-intensive EoP intervention as opposed to the low-intensive intervention.

Reproducibility and relationship of single-joint strength vs multi-joint strength and power in aging individuals.

INTRODUCTION: Reliable and sensitive muscle strength/power assessments are essential when evaluating age-related and/or training-induced changes in maximal strength and power. AIM: To investigate the reproducibility and inter-relationship of single-joint isokinetic/isometric leg muscle strength vs multi-joint mechanical muscle function during counter-movement jump (CMJ) in moderately trained aging individuals (age 72.3+/-6.6). RESULTS: The within-subject coefficient of variation (CV(w-s)) for the single-joint test showed good reproducibility (<10%) for quadriceps and hamstring strength (except for hamstring isometric). Plantar flexion demonstrated good to moderate reproducibility (CV(w-s) range: 10.4-17.2%). Excellent to good CV(w-s) (<10%) was observed for all concentric CMJ parameters, except for plantar flexor mean work (CV(w-s)=13%). Eccentric CMJ parameters demonstrated good to moderate reproducibility (CV(w-s) range: 8.1-18.2%). Isokinetic and isometric quadriceps, hamstring and plantar flexor single-joint strength measurements were found to correlate with several CMJ parameters. CONCLUSION: Single-joint and multi-joint strength and power assessment tests of the lower limbs appear to be reproducible in aging individuals. Furthermore, associations between single-joint strength and multi-joint CMJ power and force variables exist. To evaluate functional capacity in elderly people further investigations must be carried out to identify specific power/strength parameters that are most tightly linked to functional performance.

Effects of training on functional performance in 65, 75 and 85 year-old women: experiences deriving from community based studies in Odense, Denmark.

The aim of the Odense training studies is to elucidate if regular physical training influences the expected decline in physical functional ability in order to assess capacity for postponing dependence in old age. All participants were healthy community-dwelling women representing three different age-cohorts of 65, 75 and 85 year-old subjects. The 65 and 85 year-old participants of the training group took part in physical class-based exercises for eight months with one session of 60 min a week, whereas the 75 year-old women trained twice a week over eight months. The multicomponent training consisted of various exercises typically involving body awareness, rhythm, aerobic performance (walking), muscle strength and muscle endurance, flexibility, reaction and balance exercises. Physical ability was measured as physical performance test (PPT), isometric muscle strength of the trunk, hip and leg, aerobic capacity and walking speed. This shows that regular training can significantly improve physical ability of elderly women with regard to PPT, maximal oxygen uptake and maximal walking speed, suggesting that both young-old and old-old women are able to benefit from regular tailored exercise training. Thus, physical training of old community-dwelling women appears to represent a prophylactic remedy that merits further research aimed at evaluating the preliminary findings of the present studies in larger, less selective groups of participants.

Maximal oxygen uptake, muscle strength and walking speed in 85-year-old women: effects of increased physical activity.

This study explores the effect of regular training on blood pressure, maximal oxygen uptake, maximal isometric muscle strength, and walking speed in the very old. A total of 55 community-dwelling women, 85-year-old, were enrolled in a training group (N = 22) or a control group (N = 33). These groups were reduced to 19 and 26 subjects, respectively, after the training period. Training was performed once a week over eight months, and consisted of various exercises with particular attention to movements important for everyday activities. Training reduced diastolic blood pressure (p < 0.05), and showed a similar trend for systolic blood pressure. Measurements of maximal oxygen uptake before the start of the training (15 mL min-1 kg-1) revealed a level close to the presumed limit for independent living (13 mL min-1 kg-1). Training improved VO2 max by 18% (p < 0.05), whereas the control group experienced a trend towards a reduction. Maximal isometric muscle strength of both the right and left leg showed a tendency to increase with training, but no significant changes were evident in the trunk flexor and extensor muscles. The training group showed a significant increase of 17% in maximal walking speed after the training period. However, one year later, without training, this improvement was reduced to 8% (p < 0.05). No major changes were observed in the control group for any of these parameters. This study demonstrates a maximal oxygen capacity in very old community-dwelling women close to a threshold level indicating dependency. Furthermore, 8 months of regular training appears to lower blood pressure, and to increase maximal oxygen uptake and maximal walking speed. This suggests that physical reactivation of the very old may reduce the risk for acquiring age-related diseases associated with an elevated blood pressure, and may improve parameters crucial for independence.

Contraction-specific differences in maximal muscle power during stretch-shortening cycle movements in elderly males and females.

Elderly people (age 75 years; n = 48 males and 34 females) were studied in order to elucidate gender differences in elderly subjects on the determinants of muscle power (force and velocity) during a stretch-shortening cycle. All subjects performed three maximal counter-movement vertical jumps using both legs, on a force platform (Kistler 9281 B). The eccentric (Ep) and concentric (Cp) phases of the jumps were analyzed. The Ep was further divided into an acceleration phase (Epacc: from the start of the downward movement to the maximal negative velocity) and deceleration phase (Epdec: from the maximal negative velocity to the end of the downward movement). Jump height for the men was higher than for the women (P < 0.001). During both Epacc and Epdec no significant differences were observed between males and females in force and power generation. However, the men had a higher peak muscle power during the Cp, which may be explained exclusively by the velocity determinant (P < 0.001). No specific gender-related strategy appeared to influence the motor pattern of the movement. The comparable eccentric force generation of the leg extensors in both genders suggests a similar ability to cope with eccentric muscle actions during everyday activities. In contrast, the marked lower capacity for concentric contractions in women may result in an impaired performance, especially in activities where intense and rapid movements are essential, for example when reversing a forward fall. This may be one reason why elderly women are more prone to falls than are elderly men.

Anal sphincter repair in patients with obstetric trauma: age affects outcome.

PURPOSE: This study was designed to determine whether advancing age affects the outcome of anal sphincter repair in patients with obstetric trauma and fecal incontinence. METHODS: Anal sphincter repair was performed on 24 patients younger than 40 (median age, 30) years and on 14 patients older than 40 (median age, 57) years. All patients had previous obstetric trauma. RESULTS: Twenty patients younger than 40 years (83 percent; 95 percent confidence interval, 63-95 percent) became continent, or incontinent to flatus only, after anal sphincter repair, whereas four patients had unchanged incontinence. Among patients older than 40 years, six patients (43 percent; 95 percent confidence interval, 18-71 percent) became continent, whereas eight patients remained incontinent (40 percent difference in functional outcome between younger and older patients; 95 percent confidence interval, 10-70 percent). CONCLUSION: Older females have a poorer outcome of anal sphincter repair for obstetric trauma compared with younger females.

Body composition in 85 year-old women: effects of increased physical activity.

This study explores whether regular training alters body composition and resting metabolism in the very old. A total of 55 community-dwelling women, 85 years old, were enrolled in a training group (N = 22) and a control group (N = 33). Training was performed once a week for eight months, and consisted of various exercises with particular attention to movements important for everyday activities. Before, immediately after, and one year after cessation of training, body composition was evaluated both by an impedance measurement and a whole body scan by dual-photon X-ray absorptiometry. Resting metabolism, assessed as energy expenditure at rest, was measured with standardized protocols by analyzing oxygen consumption and carbon dioxide production. Height declined in both groups throughout the study. Immediately after the training period, body weight showed a trend towards reduced levels in the training group, and an opposite trend in the control group. The control group showed an increased body mass index (p < 0.05) related to an increase in fat mass immediately after the training period; these parameters were unaltered in the training group. A reduction in fat free mass (p < 0.05) and bone mineral content (p < 0.05), and unaltered energy expenditure at rest were evident in both groups during the course of the study. These results suggest that regular training can counteract the age-related accumulation of fat in the very old. Physical reactivation, therefore, may possess an important potential for reducing morbidity in the very old by lowering fat mass, and thereby reducing the risk of acquiring several age-related diseases.

Stress response to endoscopy.

BACKGROUND: Upper gastrointestinal endoscopy is often accompanied by tachycardia, which may lead to myocardial ischaemia. The pathogenesis for tachycardia is unknown, but the classic endocrine stress response may be of importance. METHODS: Seventeen patients (median age, 60 years) undergoing diagnostic gastroscopy without sedation or supplemental oxygen therapy were monitored by means of electrocardiogram, blood pressure, and pulse oximetry from 20 min before to 2 h after the procedure. Blood concentrations of glucose, cortisol, epinephrine, and norepinephrine were measured before, during, and after the endoscopy. Anxiety level was rated before the examination. RESULTS: Endoscopy was followed by a significant increase in norepinephrine and cortisol levels concomitant with a significant peak in heart rate (76 to 90 min(-1)) and mean arterial blood pressure (97 to 111 mmHg). Epinephrine was significantly reduced after the endoscopic procedure. We found no changes in glucose level or in arterial oxygen saturation. None of the patients developed signs of myocardial ischaemia during the procedure. There was no correlation between preendoscopy anxiety and the different stress variables (P > 0.3). CONCLUSIONS: The endoscopic procedure induces a classic endocrine metabolic stress response, probably causing the observed tachycardia.