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Results for “Physiological parameters”

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PubMed1975

Effect of cross-reinnervation on physiological parameters and on properties of myosin and sarcoplasmic reticulum of fast and slow muscles of the rabbit.

Cross-reinnvervation of fast (extensor digitorum longus) and slow (soleus) twitch muscles of the rabbit showed essentially complete fast to slow and slow to fast conversion, respectively, 11-12 mo after surgery with respect to a number of physiological parameters including intrinsic shortening, velocity, and isometric twitch time to peak. There was pronounced bu incomplete biochemical conversion as judged by Ca2+ uptake by sarcoplasmic reticulum, myosin ATPase, alkali lability, and light chain complement. The question of trophic substances of neural origin is discussed in light of the fact that chronic stimulation for 15 wk of a fast muscle produces complete biochemical and physiological conversion to the slow type.

Adenosine Triphosphatases↗

PubMed1999

Articular cartilage in the knee: mapping of the physiologic parameters at MR imaging with a local gradient coil--preliminary results.

The authors designed and constructed a local gradient coil that produces large gradients and short rise times and connects to their clinical system. In a cadaveric patellar cartilage specimen, the coil was used to acquire images of the physiologic parameters T1, T2, proton density, and apparent diffusion coefficient. Variations in these parameters were evident in regions of normal and abnormal cartilage.

Cartilage, Articular↗

PubMed1986

Effects of continuously expanding intracranial lesions on vital physiological parameters. An experimental animal study.

The work described in this report confirms and extends the results described in a preliminary communication (Löfgren, J. and Zwetnow, N.N., Acta Neurol. Scand. (1970, 625) which examined the effects in cats of an expanding mass, in the form of an intracranial supratentorial balloon, on vital physiological parameters. In the present study, particular emphasis was placed on the possible significance of the rate of expansion of the mass in the range usually encountered in the clinical situation of intracranial haemorrhages. Results from the experiments on 37 cats and 8 dogs showed that changes in vital parameters appeared when the balloon had reached a volume of about 5% of the intracranial volume (the "reaction volume") while respiratory arrest occurred at an intracranial volume of about 10% (the "apnoea volume"). Both threshold volumes were independent of the rate of expansion within the range used. Alterations in EEG, heart rate, respiratory rate and systemic arterial pressure usually occurred simultaneously with the development of a transtentorial pressure gradient. When respiratory arrest occurred, the cerebral perfusion pressure was markedly reduced, usually to a value of about 30 mm Hg, suggesting that brain tissue ischaemia is an important component in the lethal mechanism underlying intracranial expanding lesions. It is proposed that the volume load tolerance of the organism towards an expanding intracranial lesion, as expressed by the reaction volume and the apnoea volume, may represent a biologically useful parameter potentially suitable for quantitative evaluation of adverse agents and therapeutic procedures.

Animals↗

PubMed1998

Measuring gastroesophageal reflux disease: relationship between the Health-Related Quality of Life score and physiologic parameters.

The Gastroesophageal Reflux Disease-Health-Related Quality of Life (GERD-HRQL) scale is a reliable, valid, responsive, and practical measure of symptom severity in patients with GERD. This type of scale is needed to determine effects of treatments and their comparison. This study defines the relationship between the GERD-HRQL score and the physiologic parameters of esophagogastroduodenoscopy, esophageal manometry, and 24-hour esophageal pH monitoring. Fifty-five patients referred for surgical evaluation of GERD answered the GERD-HRQL, a nine-item ordinal-scaled questionnaire. They were evaluated with esophagogastroduodenoscopy, esophageal manometry, and 24-hour pH monitoring. The relationships among these results were determined by linear regression analysis. There were no correlations between lower esophageal sphincter (LES) and any of the pH monitoring parameters (all r < 0.25, P > 0.2), esophagitis grade (r = -0.21, P = 0.2), nor any individual GERD-HRQL item score nor total score (all r < 0.2, P > 0.11). There were correlations between all the pH monitoring parameters and esophagitis grade (all r > 0.6, P < 0.001), but not with any of the GERD-HRQL item scores or total score (r < 0.3, P > 0.15). Six of the nine items scores and the total GERD-HRQL score correlated with esophagitis grade (all r > 0.4, P < 0.01). LES pressure is a poor indicator of symptom severity, the amount of reflux, and esophageal mucosal damage. pH monitoring-measured reflux and GERD-HRQL-measured symptom severity correlate well with mucosal damage. If the goals of GERD treatment are to relieve symptoms and reverse mucosal damage, the GERD-HRQL score and 24-hour pH monitoring are better outcome measures than the LES pressure. In an era of cost containment, the GERD-HRQL may be an adequate outcome measure.

Attitude to Health↗

PubMed1989

Body weight, tick burden (Boophilus microplus), physiological parameters and reproductive efficiency of crossbred zebu cattle.

Body weight at calving, degree of tick load (Boophilus microplus), rectal temperature, respiratory frequency and heart rate were evaluated and correlated to reproductive efficiency in 63 F1 Brown Swiss x Nellore milked animals reared in the tropical region of Peru. Cows were bred by free natural service, and first ovulation was estimated by progesterone measurements. The physiological parameters were registered at morning milking (04.00 to 06.00) at an average air temperature of 22.4 +/- 0.9 degrees C. The intervals from parturition to first ovulation and conception were significantly affected when the body weight at calving was lower than 400 kg (p less than 0.01). The degree of tick burden, rectal temperature (38.4 +/- 0.2 degrees C, mean +/- s.e.), respiratory rate (25.2 +/- 0.3 breaths/min) and heart rate (66.7 +/- 0.4 beats/min) were not related to post-partum reproductive efficiency. The average intervals from parturition to first ovulation and to conception were 56.3 +/- 55.5 and 77.7 +/- 46.0 days mean +/- s.d.), respectively. The fertility rate was 85.7%. The results indicate the F1 cross to be well adapted to the given environment. It remains to be determined whether higher levels of temperate blood can be used without an accompanying decrease in reproductive performance.

Animals↗

PubMed2005

Physiological parameters that affect the transfer of radiocaesium to ruminants.

Recently there has been a renewed interest in biological scaling relationships between parameters, such as those between, for example, body mass, dry matter intake and biological half-times of radionuclides that are useful in predicting the transfer of radiocaesium to different animal species, particularly to wild animals. However, there is still a considerable unexplained variability in transfer coefficient estimates between individuals of the same species. This paper discusses the physiological parameters that affect the transfer of radiocaesium to ruminants, and it shows how a better understanding of these parameters may help to reduce the within-species variability in radiocaesium transfer coefficients. In light of the improved understanding during the past 10-15 years of the importance of source-dependent bioavailability on absorption of radiocaesium from the gastrointestinal tract, it is concluded that further studies are required on the effects of feed digestibility and physiological factors on absorption and endogenous faecal excretion of radiocaesium to better understand the variability in transfer coefficients.

Animals↗

PubMedDate not supplied

Effects of chronic hypoxia on behavioral and physiological parameters.

Aging is a process accompanied by progressive susceptibility to disturbances and impairments in adaptability. The influence of age on the capacity to adapt to chronic normobaric hypoxia (10%) was studied in 4, 20 and 27 month old rats. Adaptation was measured for four days by food and fluid intake and spontaneous activity. In addition the values of the pO2, pCO2, pH-value, Na+ concentration and hematocrit were determined. The results show an initial marked decline for the three modalities of behavior in all age groups. While age-dependent differences were exhibited, for the adaptation course in nourishment and spontaneous activity, the values of the blood gases and hematocrit did not reveal age-related changes. Thus, physiological parameters and behavior are not consistent regarding the effects of age on adaptation capacity.

Adaptation, Physiological↗

PubMed1994

[Hypoxia-radiotherapy: the changes in selected physiological parameters of healthy tissue during the breathing of a hypoxic gas mixture].

BACKGROUND: Chronic hypoxia in tumors is generally accepted to be one of the most important factors concerning sensibility to irradiation. The principle of hypoxyradiotherapy is to achieve a limited (maximal 30 min) radioresistance of the healthy (actually euoxic) tissue by acute aerogen hypoxia, without protecting effects in the average chronic hypoxic tissue of the tumor. This study investigates changes in selected physiological parameters in vivo during acute aerogen hypoxia. PATIENTS AND METHODS: In 31 persons (group A) we documented changes in blood-gas-analysis, ECG-parameters, blood pressure and pulse during acute hypoxia lasting 5 minutes. During 30 minutes of acute hypoxia we determined in another 10 persons (group B) the relations between different phosphoryl-metabolites by means of 31-phosphorus magnetic resonance spectroscopy (31P-MRS). The 31P-MRS of the Musculus triceps surae was performed on our 1.5 T imaging system (Magnetom, Siemens) using a 8 cm diameter surface coil. To achieve the hypoxic condition in the persons tested, a gas-mixture with 8.2% O2 was used. RESULTS: In group A the acute hypoxia led to significant changes in O2-pressure, the blood O2-saturation and pulse frequency. The pO2-values drop in the 5th minute to about 50% of the initial value. Concerning group B the relations of the phosphoryl metabolites show no significant changes during acute hypoxia. CONCLUSIONS: The results show an excellent tolerability of breathing of the hypoxic gas-mixture, and confirm that this mixture containing 8.2% of O2 ensures a decrease in the pO2-levels of more than 50%. This is necessary to achieve a dose modifying factor (DMF) of at least 1.15 to 1.2. The changes in relations of phosphoryl metabolites seem to reflect the ability of healthy tissue to adapt to hypoxic conditions starting after 10 minutes and leading to the loss of the radioprotective effect after 30 minutes.

Acute Disease↗

PubMed1987

Effects of capsaicin on release of substance P-like immunoreactivity and physiological parameters in isolated perfused guinea-pig heart.

Release of substance P-like immunoreactivity (SP-LI) was measured from isolated perfused guinea-pig hearts. Capsaicin (1 microM) caused a substantial increase in the amount of SP-LI detected in perfusate compared to values during exposure to vehicle or drug-free buffer. Tachyphylaxis developed to the effect of capsaicin on release of SP-LI and to its effect on physiological parameters. These data show SP-LI can be released from cardiac sensory nerves and suggest SP could mediate a portion of the response of the isolated heart to capsaicin.

Animals↗

PubMedDate not supplied

Effect of sildenafil on subjective and physiologic parameters of the female sexual response in women with sexual arousal disorder.

Sexual dysfunction is a complaint of 30-50% of American women. Aside from hormone replacement therapy, there are no current FDA-approved medical treatments for female sexual complaints. The goal of this pilot study was to determine safety and efficacy of sildenafil for use in women with sexual arousal disorder (SAD). Evaluations were completed on 48 women with complaints of SAD. Physiologic measurements, including genital blood flow, vaginal lubrication, intravaginal pressure-volume changes, and genital sensation were recorded pre- and postsexual stimulation at baseline and following 100 mg sildenafil. Subjective sexual function was assessed using a validated sexual function inventory at baseline and following 6 weeks of home use of sildenafil. At termination of the study patients also completed an intervention efficacy index (FIEI). Following sildenafil, poststimulation physiologic measurements improved significantly compared to baseline. Baseline subjective sexual function complaints, including low arousal, low desire, low sexual satisfaction, difficulty achieving orgasm, decreased vaginal lubrication, and dyspareunia also improved significantly following 6 weeks home use of sildenafil. Sildenafil appears to significantly improve both subjective and physiologic parameters of the female sexual response. Double-blind, placebo-controlled studies are currently in progress to further determine efficacy of this medication for treatment of female sexual dysfunction complaints in different populations of women.

Adult↗

PubMed2001

Management of acute physiological parameters after stroke.

Considerable effort has been directed towards acute stroke research with numerous drug therapies being tried and tested. As yet there is still no routine treatment that is unequivocally effective in acute stroke. The development of stroke units has been a major breakthrough in reducing disability through co-ordinated rehabilitation, and new interest is being focussed towards limiting acute neurological deterioration through acute stroke units. Monitoring and attempting to stabilize acute physiological parameters within normal limits such as blood pressure, temperature, hydration status, glucose levels and oxygen saturations, has become standard practice for some acute stroke units. Strategies to correct hypertension, hypotension, dehydration, hyperglycaemia, pyrexia and hypoxia may potentially reduce neuronal damage in the acute phase of stroke and subsequently improve functional outcome and survival. Whether we require large prospective randomized controlled trials to test whether these specific interventions are to be used in mainstay practice is unclear.

Aged↗

PubMed2001

Vigilance on the civil flight deck: incidence of sleepiness and sleep during long-haul flights and associated changes in physiological parameters.

The study investigated sleepiness and sleep in aircrew during long-haul flights. The objectives were to identify loss of alertness and to recommend a practical approach to the design of an alerting system to be used by aircrew to prevent involuntary sleep. The flights were between London and Miami, covering both day- and night-time sectors, each with a duration of approximately 9 h. The subjects were 12 British Airways pilots. Various physiological variables were measured that could potentially be used to indicate the presence of drowsiness and involuntary sleep: brain electrical activity (electroencephalogram, EEG), eye movements via the electro-oculogram (EOG), wrist activity, head movements and galvanic skin resistance. The EEG and EOG identified sleepiness and sleep, as well as being potential measures on which to base an alarm system. Ten pilots either slept or showed evidence of sleepiness as assessed by the EEG and EOG. Many of the episodes of sleepiness lasted < 20 s, which could mean that the subjects were unaware of their occurrence and of the potential consequences on performance and vigilance. All physiological parameters showed changes during sleep, although only the EEG and EOG were modified by sleepiness. During sleep, skin resistance was increased, and wrist activity and head movements were absent for long periods. The study indicated that the measurement of eye movements (either alone or in combination with the EEG), wrist activity or head movement may be used as the basis of an alarm system to prevent involuntary sleep. Skin resistance is considered to be unsuitable, however, being related in a more general way to fatigue rather than to sleep episodes. The optimal way to monitor the onset of sleep would be to measure eye movements; however, this is not feasible in the flight deck environment at the present time due to the intrusive nature of the recording methodology. Wrist activity is therefore recommended as the basis of an alertness alarm. Such a device would alert the pilot after approximately 4-5 min of wrist inactivity, since this duration has been shown by the present study to be associated with sleep. The possibility that sleep inertia (reduced alertness immediately after awakening from sleep) could follow periods of sleep lasting 5 min needs to be considered. The findings reported here might be applicable to other occupational environments where fatigue and sleepiness are known to occur.

Adult↗

PubMed1981

Response of hypertrophied myocardium to ischemia: correlation with biochemical and physiological parameters.

The increased susceptibility of hypertrophied hearts to ischemic injury during cardiac operations has long been recognized. Although the imbalances in oxygen supply and demand which may occur with hypertrophy during hypotension, ventricular fibrillation, or reperfusion have been extensively studied, the biochemical response of hypertrophied myocardium to ischemia has not been fully elucidated. In the present investigation, rat hearts in which hypertrophy was induced by chronic pressure overload were used to examine the relationship of the physiological parameter, ischemic contracture, to high-energy phosphate content and mitochondrial function during global ischemia. Hypertrophied hearts developed ischemic contracture after significantly shorter duration of ischemia than did normal hearts (5.8 +/- 0.3 minutes versus 10.1 +/- 0.7 minutes). High-energy phosphate content was lower in hypertrophied hearts at control and at ischemic contracture initiation and completion than in normal hearts, whereas mitochondrial function was consistently greater in the hypertrophy group. This investigation demonstrates that the hypertrophied myocardium, independent of flow-related events, is more vulnerable to ischemic injury than normal myocardium and suggests that the increased susceptibility may result from lower high-energy phosphate stores present at the onset of ischemia. The results emphasize the need for rapid cardiac arrest with the induction of ischemia in hypertrophied myocardium and suggest the potential for increasing myocardial high-energy phosphate content in the hypertrophied ventricle by interventions such as arrested perfusion with substrate containing oxygenated cardioplegic solutions prior to the onset of planned ischemia.

Animals↗

PubMed2001

Na,K-atpase alterations in diabetic rats: relationship with lipid metabolism and nerve physiological parameters.

Type 1 diabetes induces several metabolic and biochemical disturbances which result in the alteration ofNa,K-ATPase, an enzyme implicated in the physiopathology of neuropathy Several fatty acid supplementations lessen this alteration. The aims of this study were to determine the possible relationships between Na,K-ATPase activity in nerves and red blood cells (RBCs) and, on one hand, the fatty acid alterations induced by diabetes in these tissues and plasma and on the other, on nerve physiological parameters. Two groups of rats, control and diabetic (n = 15), were sacrified 8 weeks after induction of diabetes with streptozotocin. Nerve conduction velocity (NCV), nerve blood flow (NBF), Na,K-ATPase activity and membrane fatty acid composition of sciatic nerves, red blood cells (RBCs) and plasma were measured. NCV, NBF and Na,K-ATPase activity in RBCs and in sciatic nerves were significantly decreased in diabetic rats. We revealed a positive correlation between Na,K-ATPase activity in sciatic nerves and both NBF and NCV and between Na,K-ATPase activity in RBCs and NBF and the same activity in sciatic nerve. Diabetes induced major changes in plasma fatty acids and RBC membranes and less important changes in sciatic nerve membranes. Na,K-ATPase activity correlated negatively with C20: 4 (n-6) and C22: 4 (n-6) levels in nerves and with C18: 2 (n-6) levels in RBCs. During diabetes, changes in the membrane fatty acid composition suggest the existence of a tissue-specific regulation, and the decrease in Na,K-ATPase activity correlates with the alteration in the level of specific fatty acids in RBCs and sciatic nerves. Modifications in the lipidic environment of Na,K-ATPase would be involved in the alteration of its activity. Na,K-ATPase activity seems to be implicated in the decrease of both NCV and NBF during diabetes.

Animals↗

PubMedDate not supplied

Acute L-thyroxine overdose; therapy with sodium ipodate: evaluation of clinical and physiologic parameters.

Two children with acute L-thyroxine overdose were treated with sodium ipodate, an oral cholecystographic agent. Initial thyroxine (T4) levels were elevated to 98.5 mcg/dL and 134.1 mcg/dL, with associated triiodothyroxine (T3) levels of 354 ng/dL and 402 ng/dL. T3 levels increased to a maximum of 662 ng/dL and 468 ng/dL. With administration of sodium ipodate, the T3 decreased with a simultaneous increase of rT3 level. Sodium ipodate effect lasted 72 hours. No toxic effect was noted. Interestingly, thyroid hormone levels correlated with systolic blood pressure but with no other physiologic parameter. Sodium ipodate appears to be a viable treatment modality for acute thyroid overdose in children.

Acute Disease↗

PubMed2002

Ammonia threshold--comparison to lactate threshold, correlation to other physiological parameters and response to training.

During standard graded exercise, blood lactate and blood ammonia levels increase in parallel and the two thresholds appear at the same relative intensity. The first part of this study aimed at comparing ammonia threshold to lactate threshold with five different graded exercise protocols. A significant difference between the two thresholds was found only in the continuous protocol with 4-min steps in which ammonia threshold appeared at a higher intensity than lactate threshold. The second part of the study investigated the correlation of ammonia threshold to some common physiological measurements. Correlation was significant with lactate threshold, ventilation threshold and endurance time. No correlation was found the anaerobic power, anaerobic capacity measurement and peak VO2. Ammonia threshold was also studied before and after endurance training and sprint training. The 8-week endurance training program was able to delay the appearance of ammonia threshold, but not the 8-week sprint training program. Findings in this study demonstrate that ammonia threshold is a physiological parameter that should be recognized and has potential to be applied for the evaluation of exercise capacity and the effectiveness of endurance training programs.

Adult↗

PubMed1975

Physiological parameters related to running performance in college trackmen.

Submaximal and maximal oxygen consumption (VO2) and heart rate (HR) were correlated with running performance in events ranging from 100 yards to 2 miles, using as subjects 20 members of a college track team. In the first of two studies (n=11) a multi-stage walking test was used to determine VO2 and HR. Max VO2 expressed in ml/kg/min, was significantly related to 1 mile run performance but not to any of the other runs. Submaximal HR was significantly related to performance in both the 1 mile and 2 mile runs. Correlations between these physiological parameters and performance in the 220, 440, and 880 yard runs were nonsignificant. Multiple R's using max VO2 (ml/kg/min) and submaximal H were .758 and 9671, respectively, for the 1 and 2 mile runs. In study two (n=9) a running test for VO2 and HR was used, which resulted in a mean max VO2 about 7 ml higher than than elicited in the walking test, implying that for trained runners a running test was a more valid test of aerobic power. Marked relationships were found between body weight and performance, positive for the 100 yard dash and negative for the 2 mile run. Submaximal HR was again significantly related to performance in the 1 and 2 mile runs. Max VO2 was positively related to 2 mile performance and negatively related to 100 yard dash performance. Multiple R's using max VO2 and submaximal HR were .799 and .925 for the 1 and 2 mile runs, respectively. Using submaximal HR and weight the multiple R's were .777 and .945, showing that these two can account for a large amount of the variance in distance running performance. In neither study was submaximal VO2 significantly related to running performance.

Body Weight↗

PubMed1998

Normal ranges of renal physiological parameters for technetium-99m mercaptoacetyltriglycine and the influence of age and sex using a camera-based method.

162 normal Chinese men and women underwent a 99mTc MAG3 renal study. Seventy-two males and 90 females were evaluated in 5 age groups: group 1, 61-80 years; group 2, 51-60 years; group 3, 41-50 years; group 4, 31-40 years, and group 5, 21-30 years. Each subject was required to fit the following criteria: (1) clinically no history of renal, urinary disorders and systemic diseases, normal blood pressure, kidney morphology, urinary examination and serum creatinine, and (2) for the gamma camera study normal hydration and renal images, and no pelvic, ureteric dilatation or retention of tracer should be found. The normal range of common physiological parameters for 99mTc MAG3 renal studies was measured in normal subjects. The effective renal plasma flow (ERPF, camera-based Schlegel method), percent function in each kidney (renal index, RI), time of peak renal parenchymal activity (Tmax) and half time of parenchymal activity following the peak (T1/2) were evaluated. The Tmax and T1/2 were determined with regions of interest over the entire kidney. The results showed that (1) between the sexes, there were no significant differences for any parameter; (2) between the age groups, the only significant difference was a decrease in ERPF, normalized for body surface area, with increasing age (group 1, 511.3 +/- 91.2; group 2, 559.5 +/- 102.1; group 3, 577.1 +/- 79.2; group 4, 607.8 +/- 101.1, and group 5, 610.2 +/- 109.2), and (3) the RI, Tmax and T1/2 were symmetrical and did not vary between the sexes or age groups (left vs. right: RI = 49.6 +/- 2.2 vs. 50.4 +/- 2.2%, Tmax = 3.63 +/- 1.13 vs. 3.75 +/- 1.11 min, and T1/2 = 5.38 +/- 1.65 vs. 5.83 +/- 1.88 min). We find that (1) ERPF for 99mTc MAG3 decreases with age in normal Chinese, which is similar to the results of Western countries, and (2) the RI, Tmax and T1/2 were symmetrical and did not vary between the sexes or age groups in normal Chinese, and are also similar to the results of Western countries.

Adult↗