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At least 595 records · Page 33Linked to original sources
PubMed1984

Familial congenital short small bowel with associated defects. A long-term survival.

In 1974, Royer et al. described a familial syndrome consisting of a short and sluggish small bowel, malrotation of the gut, and pyloric stenosis. These authors stressed the uniformly fatal outcome of their four cases, as well as other possibly unrecognized cases previously described in the literature. The present report deals with two more familial cases, of which one represents a long-term survivor of the syndrome. The intensive work of maintaining nutrition, controlling infection, and managing the complications of associated defects are described.

Abnormalities, Multiple↗
PubMedDate not supplied

The marathon: dietary manipulation to optimize performance.

Despite pronounced involvement of the cardiovascular and respiratory systems during the marathon, the limiting factor for this event revolves around the supply and utilization of intramuscular and extramuscular fuel reserves. The single most consistently observed factor contributing to fatigue at work intensities selected by marathon runners is the depletion of muscle's endogenous carbohydrate, glycogen. Dietary manipulations which reduce the rate of muscle glycogen degradation will, therefore, spare this important fuel and delay fatigue. The purpose of this paper will be to review dietary factors which are pertinent to fuel utilization in order to optimize marathon performance.

Dietary Carbohydrates↗
PubMed2003

A single-tube multiplex reverse transcription-polymerase chain reaction for detection and differentiation of vesicular stomatitis Indiana 1 and New Jersey viruses in insects.

A multiplex single-tube reverse transcription-polymerase chain reaction (RT-PCR) has been developed for the detection and differentiation of vesicular stomatitis viruses (VSV), Indiana 1 and New Jersey, from insect samples. Using this assay, detection of either or both viruses in as little as 20 fg of total RNA from tissue culture was achieved, along with detection of vesicular stomatitis (VS) RNA from macerates containing 2 infected mosquitoes in pools of 10-30 noninfected mosquitoes. Vesicular stomatitis virus was detected by RT-PCR in all culture-positive samples, and detection as low as 4 plaque forming units per milliliter was achieved. Comparison between RT-PCR and tissue culture revealed that RT-PCR was able to detect VSV in a volume of insect macerate averaging almost 100 times less than that required for detection by tissue culture. The reported RT-PCR is a potential valuable tool for rapid and sensitive detection and differentiation of VS in insects because intense work associated with viral isolation, the cytotoxicity of insect extracts, and separate virus identification steps can be avoided. Potential application to detection and differentiation of VSV serotypes from vertebrate hosts is addressed.

Animals↗
PubMed2005

Determination of caspase-3 activation fails to predict chemosensitivity in primary acute myeloid leukemia blasts.

BACKGROUND: Ex-vivo chemosensitivity tests that measure cell death induction may predict treatment outcome and, therefore, represent a powerful instrument for clinical decision making in cancer therapy. Such tests are, however, work intensive and, in the case of the DiSC-assay, require at least four days. Induction of apoptosis is the mode of action of anticancer drugs and should, therefore, result in the induction of caspase activation in cells targeted by anticancer therapy. METHODS: To determine, whether caspase activation can predict the chemosensitivity, we investigated enzyme activation of caspase-3, a key executioner caspase and correlated these data with chemosensitivity profiles of acute myeloid leukemia (AML) blasts. RESULTS: There was, however, no correlation between the ex-vivo chemosensitivity assessed by measuring the overall rates of cell death by use of the DiSC-assay and caspase-3 activation. CONCLUSION: Thus, despite a significant reduction of duration of the assay from four to one day, induction of apoptosis evaluated by caspase-3 activity does not seem to be a valid surrogate marker for chemosensitivity.

Adult↗
PubMed2005

Determinants of oxidative phosphorylation onset kinetics in isolated myocytes.

At the onset of constant-load exercise, pulmonary oxygen uptake (VO(2)) exhibits a monoexponential increase, following a brief time delay, to a new steady state. To date, the specific factors controlling VO(2) onset kinetics during the transition to higher rates of work remain largely unknown. To study the control of respiration in the absence of confounding factors such as blood flow heterogeneity and fiber type recruitment patterns, the onset kinetics of mitochondrial respiration were studied at the start of contractions in isolated single myocytes. Individual myocytes were microinjected with a porphyrin compound to allow phosphorescent measurement of intracellular PO(2) (P(i)O(2), an analog of VO(2)). Peak tension and P(i)O(2) were continuously monitored under a variety of conditions designed to test the role of work intensity, extracellular PO(2), cellular metabolites, and enzyme activation on the regulation of VO(2) onset kinetics.

Animals↗
PubMed2006

Increases in blood flow and shear stress to nonworking limbs during incremental exercise.

PURPOSE: Regular exercise augments endothelium-dependent vasodilatory capacity in the vasculature located in the nonworking limbs. We determined whether blood flow as well as shear stress would change in inactive limbs during acute incremental exercise. METHODS: Eight young healthy female subjects performed graded exercise on arm and leg cycle ergometers that had been modified to minimize the movement of nonworking limbs and to facilitate the placement of Doppler transducers. Both brachial and femoral blood flow was monitored using Doppler ultrasonography. EMG activity was also measured to document that there was no muscular activity in nonworking muscles. RESULTS: During leg exercise, brachial blood flow and calculated shear stress gradually and curvilinearly increased (P < 0.05). At the peak work rate, there was an approximately fourfold increase in blood flow in the brachial artery (19 +/- 6 vs 77 +/- 16 mL x min(-1)). Femoral blood flow and calculated shear stress increased progressively and linearly during arm exercise (P < 0.05). CONCLUSION: We concluded that blood flow to the nonworking limbs increases markedly in proportion to the work intensity. These results suggest that the conduit arteries in the nonworking limbs are exposed to increases in blood flow and shear stress during exercise.

Adult↗
PubMed1994

Multiparametric classification of muscle T1 and T2 relaxation times determined by magnetic resonance imaging. The effects of dynamic exercise in trained and untrained subjects.

Muscle relaxation times can now be measured accurately with magnetic resonance imaging (MRI), distinguishing working muscles from non-working muscles. A correlation between T2 increase and work intensity has been shown in healthy volunteers. The small amount of data on T1 relaxation times is contradictory. In addition, all the published studies have concerned short-duration exercise in subjects of unknown training level. The goals of this study were (i) to determine T1 and T2 variations in thigh muscles after long dynamic exercise, (ii) to analyse the effects of training and (iii) to determine the relationship between power output and relaxation times after exercise. Sedentary men, soccer players and tri-athletes performed submaximal dynamic exercise at a constant heart rate for 15 min. MRI was performed before and 5 min after the end of exercise. The results showed (i) that T1 increased in parallel to T2 in anterior thigh muscles and (ii) that multiple correspondence analysis and hierarchical ascending classification can discriminate three subjects classes according to power output, training level and relaxation times, which fitted well with our three groups of subjects.

Adolescent↗
PubMed2001

Dynamics of left ventricular diastolic filling during exercise: a Doppler echocardiographic study of boys 10 to 14 years old.

STUDY OBJECTIVE: Factors influencing diastolic filling of the left ventricle may serve as critical determinants of both maximal cardiac output and oxygen uptake. This study was conducted to assess diastolic filling dynamics of the left ventricle during progressive upright cycle exercise in children. METHODS: Twelve boys aged 10 to 14 years underwent cycle testing with determination of transmitral flow velocities and pressure gradients as well as cardiac stroke volume using Doppler echocardiography. RESULTS: Estimated diastolic filling period shortened from 0.479 +/- 0.043 s at rest to 0.138 +/- 0.015 s at peak exercise. The peak and mean transmitral pressure gradient rose fourfold from rest to peak exercise. Mitral flow volume per beat rose by only 40% and remained stable beyond mild-to-moderate intensity work. CONCLUSIONS: Increases in transmitral pressure gradient with exercise may serve principally to augment velocity of ventricular filling with the progressively shortening diastolic time period.

Adolescent↗
PubMed1984

[Corticotropin-releasing factor concentrations in cerebrospinal fluid and its diurnal rhythm in patients with Cushing's disease].

Since Vale et al isolated and sequenced a 41 amino acid peptide with corticotropin-releasing factor (CRF) activity from ovine hypothalami, intensive works have been done about its physiological activity and intracerebral distribution. However, little has been done yet about CRF metabolism in human cerebrospinal fluid (CSF). Using a specific ovine CRF radioimmunoassay (RIA), we measured the levels of CRF in CSF from 16 patients with Cushing's disease (group I), 8 patients with Acromegaly (group II), 5 patients with Prolactinoma (group III) and 10 patients without endocrine abnormalities (group IV). Moreover diurnal changes of CRF in CSF from 2 patients with Acromegaly and 2 patients with Cushing's disease were examined. Dilution curves of CRF in CSF were parallel to that of synthetic ovine CRF standard. The intraassay coefficient of variation was 9.2% and the interassay coefficient of variation 12.6%. The concentrations of CRF in CSF of groups I, II, III and IV were 38.83 +/- 9.02 pg/ml (mean +/- SD), 44.24 +/- 4.71, 47.62 +/- 8.05 and 49.45 +/- 12.86, respectively. Group I was significantly lower than group IV (p less than 0.05). On the other hand, group II or III was not significantly different from group IV. A diurnal rhythm of CRF in CSF was observed in 2 patients with Acromegaly. However, there was almost no change in the 2 patients with Cushing's disease. In considering rich amount of CRF in hypothalamus and CRF-positive fibers surrounding the third ventricle, CRF content in CSF seems to reflect mainly its metabolic activity in hypothalamus.(ABSTRACT TRUNCATED AT 250 WORDS)

Acromegaly↗
PubMed2006

Development of new cancer therapeutic agents targeting mitosis.

Targeting cellular proliferation persists as a mainstay of cancer therapeutic strategy. Although microtubule-targeting drugs (such as taxanes and vinca alkaloids) have been used successfully in the clinic to treat a variety of cancers, they carry substantial liabilities that have spurred drug companies to aggressively pursue new tubulin-targeting drug candidates with improved efficacy and toxicity profiles. The recent discoveries of new mitotic targets for cancer therapy (such as kinesin spindle protein, Aurora kinases and Polo-like kinase-1) have also stimulated intense work focused on identifying novel antimitotic drugs directed at these new targets. A number of novel antimitotic drugs have demonstrated encouraging activity in preclinical models and have progressed into clinical development. This review focuses on selected new antimitotic drugs under evaluation in clinical trials.

Animals↗
PubMed1988

[Changes in blood toluene concentrations in rats under various kinds of exposure conditions and physical loads].

The present experiment was conducted under the assumption that exposure conditions (time of exposure, concentration of exposed substances and working intensity) should be taken into account in estimating the level of invasion of injurious substances into the human body. Experiments were carried out on rats under various exposure conditions of toluene and the toluene concentration in the blood was monitored for the estimation of its intake. The results were as follows; 1. It was confirmed that toluene concentration in blood increased and plateau-time was delayed in proportion to increase in exposure concentration. 2. Light exercise (5.0, 7.0 m/min) increased toluene concentration in blood and it was proportioned to intensity of physical exercise. 3. Light daily exercise (2.7 m/min) for six days increased toluene concentration in blood gradually day after day when compared to exposure without exercise, though the exposure conditions were the same every day. It is thus considered that physical exercise is one of the very important factors in estimation of exposure.

Animals↗
PubMed1998

Injuries sustained during competitive white-water paddling: a survey of athletes in the 1996 Olympic trials.

To examine injury prevalence in competitive paddlers, a cross-sectional, retrospective, written survey of the athletes competing in the four regional Olympic canoe and kayak qualifying races for the United States Canoe and Kayak Team was conducted in the spring of 1996. A total of 375 questionnaires were distributed, of which 54 were completed and returned. Results were reported as the percentage of total injuries. A composite of 271 separate injuries was reported by kayakers during their careers. While 56% of the injuries occurred during training, 40% happened during recreation and 4% during competition. The most frequent injuries were sprains (32%), tendonitis (20%), and chronic musculoskeletal pain (14%). Simple bruises (9%) and infections (8%) occurred with moderate frequency, while severe injuries, such as dislocations (3%) and lacerations (2%), were even less common. About 10% of the paddlers noted a near-drowning event during their careers. Of the injuries noted, 70% were reported as recurrent or chronic. Treatment included rest (37%), physical therapy (23%), medical intervention (34%), and surgical intervention (6%). White-water paddling of canoes and kayaks is a potentially dangerous sport, and competitive paddlers frequently suffer a range of injuries. Most injuries occurred during training; however, the short intense work of racing produced a greater frequency of injuries.

Adult↗
PubMed2004

High-throughput proteomics using antibody microarrays.

Antibody-based microarrays are a novel technology that hold great promise in proteomics. Microarrays can be printed with thousands of recombinant antibodies carrying the desired specificities, the biologic sample (e.g., an entire proteome) and any specifically bound analytes detected. The microarray patterns that are generated can then be converted into proteomic maps, or molecular fingerprints, revealing the composition of the proteome. Using this tool, global proteome analysis and protein expression profiling will thus provide new opportunities for biomarker discovery, drug target identification and disease diagnostics, as well as providing insights into disease biology. Intense work is currently underway to develop this novel technology platform into the high-throughput proteomic tool required by the research community.

Antibodies↗
PubMed2004

The level of physical activity and the growth hormone (GH) response to acute physical exercise.

There is no clear evidence about the influence of programmed physical activity (training) on growth hormone (GH) response to acute physical exercise. The aim of this study was to estimate the relationship between the level of physical activity and the serum growth hormone concentration in response to acute physical exercise. The study was performed on 20, healthy male subjects. Based on the level of their physical activities they were divided in two groups of equal size: group 1, trained, and group 2, untrained subjects. All subjects performed one boot of exercise on cycle ergometer, lasting 30 minutes. Work intensity was approx. 65% of VO2 max, and the rate of cycling was 60/min. Serum GH concentrations were measured by IRMA (immunoradiometric assays) method in blood samples obtained in the period of rest, during exercise and in the recovery period. There were marked differences in the dynamics of changes in the serum GH concentrations during exercise period between the groups of various level of physical activity despite the lack of the significant differences in basal level and maximal level of serum GH concentration at the end of exercise. Untrained subjects showed faster increase in serum GH concentration than trained subjects, but in trained subjects the restoration of the basal values in the recovery period was faster. These results indicate that the level of physical activities in young, healthy male subjects has no influence on GH response to acute physical exercise.

Adaptation, Physiological↗
PubMed2006

Serum growth hormone and glucose levels in acute exercise and in the recovery period in athletes.

Growth hormone exerts several metabolic effects, including effects on proteins, fats and carbohydrates. Among the many metabolic activities of GH, two contradictory actions were described: acute and early insulin-like activity and chronic and late anti-insulin like activity also called diabetogenic activity. A dramatic increase in plasma concentration of GH was found during endurance exercise, but its role during exercise is not well known. According to its metabolic effects a possible role of growth hormone may be in maintenance of glucose level during exercise. The aim of this study was to analyze dynamics of changes in GH and glucose levels during acute workload and in the recovery period, in a group of well trained athletes. All the subjects exercised for 30 minutes on cycle ergometer in sitting position (work intensity 50% of VO2 max, RPM 60/min). Serum GH concentrations were measured by IRMA (immunoradiometric assays) method in blood samples obtained at rest and 6-min intervals during exercise, and 15-min intervals during recovery period. Serum glucose levels were determined by standard enzymatic method glucose oxidase (GOD PAP) at the same intervals. There were no correlations between serum GH and glucose levels either during exercise or in the recovery period. There were no differences between glucose levels during exercise, so we can not exclude possible role of GH in glucose concentration maintenance.

Adult↗
PubMed1995

Calculation of mean arterial pressure during exercise as a function of heart rate.

Mean arterial blood pressure (MAP) is a common characteristic of the cardiac cycle. Usually it is evaluated by assuming that the left ventricular ejection time (systole) constitutes a constant proportion of the cardiac cycle (i.e. 1/3), regardless of the heart rate (HR). However, elevation of HR during exercise results in a reduction of the duration of the ejection period and even a greater reduction of the ventricular filling period. Therefore, a constant diastole/systole proportion at various heart rates may be misleading. The purpose of this study was therefore to evaluate the accurate proportion of the systolic period from the cardiac cycle at different metabolic rates and calculate MAP accordingly. Twenty healthy subjects (age: 20-50 yr.) exercised at different work intensities on a cycle ergometer to elicit HR in the range of 55-180 bpm. During the ride the mitral and aortic flow velocity wave form were recorded by Doppler echocardiography; the mitral flow from the apical view and the aortic flow from the apical long axis view. Blood pressure was measured using a sphygmomanometer. The fraction of systole (St) from the heart cycle was related to HR and was described in mathematical terms as: St = 0.01exp(4.14-40.74/HR) MAP was then calculated from the diastolic blood pressure (dBP) and the pulse pressure (PP) adjusted for St as follows: MAP = dBP+St.PP; (mmHg) The use of the suggested model reduces errors in the evaluation of various cardiac parameters which are related to arterial pressure, such as peripheral resistance, especially under exercise-heat stress.

Adult↗
PubMed1993

Effects of head cooling on cardiovascular and body temperature responses during submaximal exercise.

Cardiovascular and body temperature responses during submaximal exercise (25% and 50% VO2max) were investigated using female subjects (n = 6) in two separate experiments; one with head cooling and heating and the other with torso heating with and without head cooling. To supply the heat load, a liquid conditioned cap and vest were used. In the first experiment, a significant decrease in heart rate, oxygen intake (VO2) and cardiac output (Q) at relative work intensity of 50% VO2max was observed by head cooling. These results show that head cooling is very effective to reduce the physiological strain. In the second experiment, Q as a function of VO2 during torso heating was decreased by head cooling. However, the tympanic membrane temperature during head cooling at 15 degrees C was significantly higher than that at 20 degrees C and it was almost the same level with torso heating without head cooling. The results suggest that excess head cooling is not beneficial in terms of improving the body heat dissipation.

Body Temperature Regulation↗
PubMed2000

Field studies on inhibitory influence of skin pressure exerted by a body compensatory brassiere on the amount of feces.

The present experiment investigated the effects of skin pressure produced by a body compensatory brassiere on defecation activity. Seven healthy females (11-41 yrs) volunteered as participants, being free of medication and constipation. The experiment lasted 3 weeks. The participants did not wear the body compensatory brassiere for the first week, wore it during waking hours for the second week, and again did not wear it for the third week. Whenever they desired to defecate, they did so and then weighted the amount of feces immediately by themselves. Eating times, daily amounts of foods and drinks, their menu, work intensity and its duration, retiring and rising time were controlled to be as similar as possible from day to day. The main finding was that the amount of feces was significantly smaller during the second week (wearing the body compensatory brassiere) than the first and third weeks (not wearing the body compensatory brassiere). These observations are discussed in terms of the suppression of the parasympathetic nervous system and intestine motility, and the delayed transit time in the large intestine.

Adolescent↗