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PubMed1989

[Stress and kinematic analysis of the head and neck in frontal collision. A comparison of voluntary probands and postmortem human test cadavers].

Investigations comparing dynamics and kinematics in volunteers and postmortem human subjects (PMHS) under the same collision conditions are rare, although such results are of elementary importance in order to estimate the suitability of PMHS as injury indicators in crash tests. Under this aspect, a report on 12 experimental frontal collisions has been made where PMHS were loaded and restrained by a 80 mm broad double shoulder lap-step belt. The impact velocity amounted 60 km/h, the mean vehicle decelerations were at 11 g and 15 g. In the Naval Biodynamics Laboratory in New Orleans, the comparing collective of 9 volunteers in the age range of 18 to 22 years has been investigated by a mean deceleration of 11 g at otherwise comparable conditions. Optical targets have been fixed at the 1st thoracic vertebra, the occiput and the top of the head in the PMHS, the collision phase has been documented by a laterally to the sled mounted high-speed camera with a frame rate of 1000 p/s. The accelerations have been measured tri-axial at the top of the head, at the clivus and the 1st thoracic vertebra. For the simulation of the muscle tonus of the volunteers, formaldehyde has been injected into the neck muscles. In the PMHS as well as in the volunteers no thoracic- or abdominal injuries occurred during the above mentioned loads. However, the spinal column of the PMHS remained uninjured only in 3 cases, in 7 cases hemorrhages in the intervertebral disc, lacerations of the ligamentum flavum or hemorrhages in the vertebral joints were observed.

Acceleration↗
PubMed1985

[Uniform theory on the pathomechanism of closed renal stalk injuries--subpelvic ureteral ruptures and kidney vascular stalk lesions].

There are no homogeneous opinions concerning the pathomechanism of closed renal stalk injuries. On the basis of a literary analysis of 168 renal vessel stalk lesions and 78 ruptures of the ureter the attempt is made to contribute to the clarification of the etiology of these injuries. Subpelvic ruptures of the ureter and renal vessel stalk lesions are regarded as a constituent of closed renal stalk injuries and traced back to a uniform pathomechanism. Deceleration traumas leading to cranial, caudal and ventral movements of the kidney are regarded as predominant cause of closed renal stalk injuries. In accidents with deceleration processes should more be thought of closed renal vessel stalk lesions and subpelvic injuries of the ureter, also when there are no blunt abdominal traumas.

Deceleration↗
PubMed1979

[The pre-ejection-period of the human fetal heart: patterns of change during labour and heart-frequency alterations (author's transl)].

UNLABELLED: The Pre-ejection period (PEP) of the cardiac cycle, fetal heart rate, and uterine contractions were monitored in a series of 115 unselected fetus sub partu. PEP was detected by a new on-line technique using EKG and DKG. This method permits a continuous registration of PEP patterns simultaneously with the fetal CTG. Any change in PEP was related to fetal status and fetal heart rate patterns. RESULTS: Absolute PEP was prolonged and relative PEP (PEP/cardiac cycle) did not alter during decelerations due to a fetal head compression. The absolute PEP and the relative PEP were prolonged (rarely relative PEP was shortened) during alterations of fetal heart rate patterns based on the alteration in hemodynamics of fetal circulation. A first increase of the PEP was followed by a second increase of the PEP during severe variable decelerations conducting to a secondary chemoreceptor-reflex caused of fetal hypoxemia and acidosis; the duration between the two prolongation peaks of the PEP is directly correlated of fetal blood oxygenation: hypoxemia decreases this duration. These changes are essentially independent of heart rate and therefore PEP can be considered as an independent parameter for fetal assessment.

Deceleration↗
PubMed1996

Occult ascending aortic rupture in the presence of an air bag.

A patient presented to the emergency department after a high-speed decelerating-type motor vehicle accident. Due to activation of his air bag device, the patient was without significant obvious injury. Upon evaluation in the emergency department he was also without any radiographic or physical signs of serious injury. In the ensuing 24 hours, severe chest pain developed, and subsequent aortography demonstrated a tear of his ascending aorta just distal to the root. Although occult injury to the aorta and great vessels does occur in a small percentage of patients, it is quite rare. However, with the advent of air bags, in the absence of associated injuries, signs, and symptoms, a high index of suspicion must be entertained in decelerating-type accidents to diagnose occult injury to the aorta and great vessels.

Accidents, Traffic↗
PubMed1983

Major pelvic fractures.

Pelvic fractures associated with blunt trauma contributed significantly to morbidity and mortality in 593 patients with high-velocity deceleration injuries. Those with open, hemorrhagic pelvic fractures required massive blood volume replacement and intensive care for long periods of time and had a 60% mortality. Patients with hemorrhagic pelvic fractures also had a notable blood replacement requirement (mean, 29 units) and a 50% mortality. Patients with open pelvic fractures without significant hemorrhage had a 25% mortality and were at an increased risk of pelvic sepsis. The overall mortality associated with pelvic fractures following high-velocity deceleration accidents was 16.6%. The identifiable causes of death in patients with pelvic fractures were associated injuries, particularly closed head injury, hemorrhage from pelvic vessels, and sepsis. An improved survival rate requires better, more prompt use of available treatment, as well as development of new and better methods of caring for severely injured patients with blunt trauma.

Adolescent↗
PubMed1997

Motor unit recruitment and discharge behavior in movements and isometric contractions.

The purpose of this study was to contrast the discharge patterns of the same motor units during movements and during isometric contractions that were produced with comparable torque-time characteristics. Subjects performed elbow flexion and extension movements with predetermined acceleration characteristics. The average acceleration and deceleration profiles for the movements were reproduced in the isometric setting by presenting the kinematic profiles as templates for torque production. Trained subjects were able to match the first agonist (AG1) and antagonist (ANT) electromyographic (EMG) bursts, but tended to produce a smaller second agonist burst (AG2) in the isometric contraction. Twenty-five motor units from triceps brachii were studied. The same motor units (with one exception) were recruited and subsequently discharged in a similar fashion in both the isometric and movement tasks in the AG1 and ANT EMG bursts, with fewer motor unit discharges in the AG2 burst in the isometric contraction. The central control mechanisms appear to be the same for the acceleration phase of movement and isometric contraction, but differ during the deceleration phase.

Adult↗
PubMed2000

Estimation of maximum increment age in height and weight during adolescence and the effect of World War II.

An attempt was made to estimate the maximum increment age (MIA) in height and weight of Japanese boys and girls during the birth years 1893-1990 through the published data of the Ministry of Education, Science, Sports and Culture in Japan. In cases where the same maximum annual increment occurred in two or three successive age classes in a birth year cohort, a new formula (see Eq. 2) was developed to estimate the MIA. The existing formula for estimating MIA was modified to remove the mathematical deficiency (Eq. 1). Estimated MIA shows an overall declining trend, except in birth year cohorts 1934-1951. The effect of World War II on MIA was investigated by a dummy variable regression model. On average, during the birth years 1934-1951, MIA in height decelerated by 1.35 years in boys and 0.54 year in girls, while MIA in weight decelerated by 0.95 year in boys and 0.78 year in girls. Am. J. Hum. Biol. 12:363-370, 2000. Copyright 2000 Wiley-Liss, Inc.

Journal Article↗
PubMed1993

Mammographic assessment of human breast cancer growth and duration.

BACKGROUND: Accumulating data from numerous sources have confirmed that breast cancers have highly variable rates of growth. Contemporary thought supports that collectively the gross rates should decelerate with increasing tumor mass. METHODS: Using composite data derived from mammographically measured growth of breast cancers observed at the Universities of Heidelberg and Louisville, the growth curve providing the best fit to the observed data, and the variance occurring around this curve has been calculated. RESULTS: A generalized logistic equation provided the best fit, with a natural variance ranging from extremely rapidly growing to slowly growing cancer. These data do not cover the entire range of growth rates because cancers appearing acutely between mammograms were observed only once, and some breast cancers never grew. CONCLUSIONS: The highly variable decelerating growth rates of breast cancers are better but incompletely defined, and these rates are of value in considering screening strategies and prognosis.

Adolescent↗
PubMed2001

Effect of airflow rate on yields of Steinernema carpocapse Az 20 in liquid culture in an external-loop airlift bioreactor.

Maximization of the contact between males and females is a key factor in the production of the nematode Steinernema carpocapsae in a bioreactor.%The influence of the airflow rate in male and female distribution and mass production in an external-loop bioreactor with a deceleration zone was studied. When operating at an airflow rate of 0.05 vvm, a high retention of females in the deceleration zone of the bioreactor was observed and a larger nematode productivity was obtained. At this aeration rate there was a higher proportion of males in that zone, which together with the lower circulation rate, increases the probability of encounters, thereby explaining the increase in productivity.

Air Movements↗
PubMed2000

Amnioinfusion for umbilical cord compression in labour.

BACKGROUND: Amnioinfusion aims to prevent or relieve umbilical cord compression during labour by infusing a solution into the uterine cavity. OBJECTIVES: The objective of this review was to assess the effects of amnioinfusion on maternal and perinatal outcome for potential or suspected umbilical cord compression or potential amnionitis. SEARCH STRATEGY: The Cochrane Pregnancy and Childbirth Group trials register and the Cochrane Controlled Trials Register were searched. SELECTION CRITERIA: Randomised trials of amnioinfusion compared with no amnioinfusion in women with babies at risk of umbilical cord compression; and women at risk of intrauterine infection. DATA COLLECTION AND ANALYSIS: Eligibility and trial quality were assessed by the reviewer. MAIN RESULTS: Twelve studies were included. Transcervical amnioinfusion for potential or suspected umbilical cord compression was associated with the following reductions: fetal heart rate decelerations (relative risk 0.54, 95% confidence interval 0.43 to 0.68); caesarean section for suspected fetal distress (relative risk 0.35, 95% confidence interval 0.24 to 0.52); neonatal hospital stay greater than 3 days (relative risk 0.40, 95% confidence interval 0. 26 to 0.62); maternal hospital stay greater than 3 days (relative risk 0.46, 95% 0.29 to 0.74). Transabdominal amnioinfusion showed similar results. Transcervical amnioinfusion to prevent infection in women with membranes ruptured for more than 6 hours was associated with a reduction in puerperal infection (relative risk 0.50, 95% confidence interval 0.26 to 0.97). REVIEWER'S CONCLUSIONS: Amnioinfusion appears to reduce the occurrence of variable heart rate decelerations and lower the use of caesarean section. However the studies were done in settings where fetal distress was not confirmed by fetal blood sampling. The results may therefore only be relevant where caesarean sections are commonly done for abnormal fetal heart rate alone. The trials reviewed are too small to address the possibility of rare but serious maternal adverse effects of amnioinfusion.

Amnion↗
PubMed2000

Amnioinfusion for meconium-stained liquor in labour.

BACKGROUND: Amnioinfusion aims to prevent or relieve umbilical cord compression during labour by infusing a solution into the uterine cavity. It is also thought to dilute meconium when present in the amniotic fluid and so reduce the risk of meconium aspiration. However it may be that the mechanism of effect is that it corrects oligohydramnios (reduced amniotic fluid), for which thick meconium staining is a marker. OBJECTIVES: The objective of this review was to assess the effects of amnioinfusion for meconium-stained liquor on perinatal outcome. SEARCH STRATEGY: The Cochrane Pregnancy and Childbirth Group trials register and the Cochrane Controlled Trials Register were searched. SELECTION CRITERIA: Randomised trials comparing amnioinfusion with no amnioinfusion for women in labour with moderate or thick meconium-staining of the amniotic fluid. DATA COLLECTION AND ANALYSIS: Eligibility and trial quality were assessed by one reviewer. MAIN RESULTS: Ten studies, most involving small numbers of participants, were included. Under standard perinatal surveillance, amnioinfusion was associated with a reduction in the following: heavy meconium staining of the liquor (relative risk 0.03, 95% confidence interval 0.01 to 0.15); variable fetal heart rate deceleration (relative risk 0.47, 95% confidence interval 0.24 to 0. 90); and a trend to reduced caesarean section overall (relative risk 0.83, 95% confidence interval 0.69 to 1.00). No perinatal deaths were reported. Under limited perinatal surveillance, amnioinfusion was associated with a reduction in the following: meconium aspiration syndrome (relative risk 0.24, 95% confidence interval 0. 12 to 0.48); neonatal hypoxic ischaemic encephalopathy (relative risk 0.07, 95% confidence interval 0.01 to 0.56) and neonatal ventilation or intensive care unit admission (relative risk 0.56, 95% confidence interval 0.39 to 0.79); there was a trend towards reduced perinatal mortality (relative risk 0.34, 95% confidence interval 0.11 to 1.06). REVIEWER'S CONCLUSIONS: Amnioinfusion is associated with improvements in perinatal outcome, particularly in settings where facilities for perinatal surveillance are limited. The trials reviewed are too small to address the possibility of rare but serious maternal adverse effects of amnioinfusion.

Amnion↗
PubMed1985

Hutterite cerebro-osteo-nephrodysplasia: autosomal recessive trait in a Lehrerleut Hutterite family from Montana.

We are reporting on two Lehrerleut Hutterite sisters who have a syndrome of congenital shortness with mild spondylorhizomelic dwarfism; later failure to thrive, ie deceleration of weight gain presumably due to CNS-based severe feeding problems; a CNS defect, probably developmental (not biochemical) with normal prenatal brain growth but later deceleration from 50th to 2nd centile associated with severe mental retardation and decorticate disturbances of neurologic function; and possible renal involvement with terminal nephrotic syndrome. This seems to be a previously undescribed pleiotropic autosomal recessive trait.

Abnormalities, Multiple↗
PubMed1986

Sexual dimorphism in mandibular growth of French-Canadian children 6 to 10 years of age.

Polynomial regression is used to model the mandibular growth of 28 girls and 26 boys who were followed longitudinally from 6 to 10 years of age. The pooled-within individual designs indicate that ramus height follows a linear pattern of size increase; corpus and total mandibular lengths display curvilineal, decelerating, patterns of growth over the age range. Multivariate analyses of variance reveal significant sex differences in size, favoring boys, for the two length measures at 6 years of age. Growth velocity for corpus length is also significantly greater in boys than in girls. Sexual dimorphism in the growth of total mandibular length is more complex, including differences in velocity and deceleration. Ramus height shows no significant pattern of variation between boys and girls for either size or growth velocity.

Aging↗
PubMed1990

Improved diastolic LV filling after acute application of ajmaline in patients with coronary artery disease and normal systolic LV function.

To determine whether ajmaline (A) can be safely applied in coronary artery disease (CAD), changes of left ventricular (LV) function after acute ajmaline application were analyzed by pulsed Doppler echocardiography in 10 CAD patients. LV pressures in systole and end-diastole and LVEF remained normal and comparable. Doppler normalized peak filling rate (p less than 0.02), peak early/atrial filling velocity (E/A) ratio (p less than 0.01) and E-deceleration (p less than 0.05) increased. The increase in E/A and in E-deceleration relative to base values was directly correlated (p less than 0.001). PEP increased, LVET remained unchanged. LV diastolic filling is improved after acute application of ajmaline in patients with CAD and normal systolic function; its application may be advised not only for therapy of arrhythmia but also to improve left ventricular diastolic mechanics in these patients.

Aged↗
PubMed1995

Effects of intravenous digoxin on pulmonary venous and transmitral flows in patients with chronic heart failure of different degrees.

Acute effects of digoxin on diastole were evaluated noninvasively by combining data simultaneously obtained by Doppler echocardiograms (echo-Doppler) of transmitral and pulmonary venous flow curves in 38 patients with dilated and failing hearts, who had been stable for at least 7 days before the study. According to the resting ejection fraction (EF), patients were subdivided into Group 1 (EF < 30%: n = 20, mean EF values 23 +/- 8%) and Group 2 (EF > or = 30%: n = 18, mean EF values 40 +/- 3%). Significant differences were observed at rest between the two groups in both transmitral (shorter deceleration time and isovolumic relaxation time and increased peak E and E/A ratio in Group 1 vs. Group 2) and transpulmonary (reduced systolic forward component and systolic fraction of the flow curves in Group 1 compared with Group 2 and control subjects) parameters. Digoxin (1 mg subdivided into two doses, each infused over a 15-min period with 2 h between the doses) significantly modified the diastolic profile in Group 1 patients in the absence of statistically relevant changes in EF: a significant decrease of transmitral peak E (from 76 +/- 17 to 60 +/- 15 cm/s, p < 0.05) and E/A ratio (from 2.5 +/- 1 to 1.6 +/- 0.6; p < 0.05) and a significant lengthening of deceleration time (from 115 +/- 20 to 160 +/- 18 ms; p < 0.05) were detected.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2000

Worsening of left ventricular diastolic dysfunction during exercise causes decreased exercise tolerance in hypertension.

BACKGROUND: Exercise tolerance is reduced in hypertension. Hypertension affects left ventricular (LV) diastolic filling by causing abnormal relaxation and decreasing compliance. HYPOTHESIS: This study was designed to determine whether worsening of LV diastolic dysfunction during exercise causes decreased exercise tolerance in hypertension. METHODS: Left ventricular diastolic filling parameters were examined at mitral valve by Doppler echocardiography at rest and at peak exercise in hypertensive patients and were compared with those of age- and gender-matched normotensive individuals. Treadmill exercise stress test was performed according to the Bruce protocol and the exercise time was recorded. RESULTS: Exercise time was significantly shorter in the hypertensive group than that in the normotensive group (320 +/- 29 vs. 446 +/- 38 s, p 0.03). The hypertensive group demonstrated abnormal relaxation pattern of diastolic mitral inflow at rest, which became pseudonormal at peak exercise (E/A velocity ratio, rest 0.86 +/- 0.06 vs. exercise 1.19 +/- 0.09, p < 0.001). The diastolic mitral inflow pattern remained normal at peak exercise in the normotensive group. The deceleration time and the pressure half time of early mitral inflow at peak exercise were significantly shorter in the hypertensive group than those in the normotensive group (deceleration time, 182 +/- 20 vs. 238 +/- 22 ms, p 0.02: pressure half time, 54 +/- 5 vs. 70 +/- 12 ms, p 0.01). CONCLUSIONS: This study demonstrates that reduced exercise tolerance in hypertension is associated with worsening of diastolic dysfunction during exercise consistent with an increase in left atrial pressure.

Compliance↗
PubMed2005

Spironolactone improves diastolic function in the elderly.

BACKGROUND: Diastolic dysfunction is common in the elderly. Increased myocardial fibrosis, a major determinant of diastolic function, has been observed with advancing age. Spironolactone prevents age-related increases in myocardial fibrosis in old normotensive rats. HYPOTHESIS: Spironolactone, via its antifibrotic activity, can improve diastolic function in the elderly with isolated diastolic dysfunction. METHODS: The study was a prospective, double-blind, randomized, placebo-controlled trial. Thirty elderly subjects between 60 and 85 years of age with isolated diastolic dysfunction and no contraindications for spironolactone were randomized to 25 mg/day of spironolactone or placebo for 4 months. Mitral E/A and deceleration time, plasma levels of carboxy-terminal of procollagen type I (PICP), and brain natriuretic peptide (BNP) were measured at baseline and at the end of 4 months. Plasma level of potassium was also monitored to prevent clinically significant hyperkalemia. RESULTS: There was no serious adverse event or clinically significant hyperkalemia in the spironolactone group. Compared with baseline values, spironolactone significantly improved mitral E/A ratio (0.71 +/- 0.08 vs. 0.84 +/- 0.19, p = 0.025) and deceleration time (285.5 +/- 73.1 vs. 230.0 +/- 54.7, p = 0.035). There were no significant differences in the magnitude of change in the levels of PICP and BNP between the two treatment groups. CONCLUSION: Spironolactone may improve diastolic function in the elderly.

Aged↗
PubMed1994

Novel touch-induced, Ca(2+)-dependent phobic response in a flagellate green alga.

The biflagellate green alga Spermatozopsis similis exhibits a remarkable avoidance reaction in addition to the photophobic or stop response characteristic of such algae. S. similis normally swims forward with its anteriorly attached flagella directed posteriorly and propagating sine-like waves base to tip. Upon contact with surfaces or other cells, S. similis responds with rapid backward swimming, covering distances of up to 50 microns in 140 to 220 msec. This reaction, which we term the mechanoshock response, also can be triggered by vigorous mechanical stimulation, but not by physiological light intensities. It consists of 3 phases: (1) a rapid acceleration phase with average duration of 31 msec; (2) a phase of about 66 msec with constant high speed (maximal velocities of > 600 microns.sec-1) or slow deceleration; and (3) a deceleration phase of approximately 83 msec, followed by a stop or short period of circling. The cells then resume forward swimming in a random direction. Prior to the mechanoshock response the flagella rapidly are brought together into a close parallel configuration extending anteriorly of the cell body. They then appear to propel the cell by undulatory beating, while the cell describes a pronounced helical path. Small decreases in the extracellular Ca2+ concentration, as well as low concentrations of Ba2+, strongly suppress the probability of this phobic reaction. We conclude that this mechanoshock response involves large Ca2+ influxes, probably mediated by mechanosensitive and/or stretch-activated ion-channel(s).

Barium↗