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Nine participants performed two bouts of a step exercise, during which the quadriceps muscle of one leg acted eccentrically. Before and after the exercise, isokinetic torque was measured over a range of knee angles to determine the optimum angle for torque. Immediately after the first bout of exercise, the quadriceps showed a significant ( P  < 0.05) shift of 15.6±1.4° (mean± s &xmacr; ) of its optimum angle in the direction of longer lengths, suggesting the presence of damage. A drop in peak torque, together with delayed soreness and swelling, confirmed that damage to muscle fibres had occurred. After the second bout of exercise, 8 days later, the shift in optimum angle was 10.4±1.0°, which was significantly less than after the first bout ( P  < 0.05). Other indicators of damage were also reduced. In addition, the muscle exhibited a sustained shift in optimum angle (3.4±0.9°), suggesting that some adaptation had taken place after the first bout of exercise. We conclude that muscles like the quadriceps can show evidence of damage after a specific programme of eccentric exercise, followed by an adaptation response. This is despite the fact that the quadriceps routinely undergoes eccentric contractions in everyday activities. [ABSTRACT FROM AUTHOR]

Objective: Serial hand-wrist x-rays were assessed for Tanner-Whitehouse 2 skeletal ages of children with cleft palate, unilateral cleft lip and palate, and bilateral cleft lip and palate. The skeletal ages were compared by cleft type to see whether growth delay might explain the small body size for age and delayed maturation sometimes seen elsewhere in children with clefts., Design: This is a retrospective study of serial x-rays collected between 1950 and 1968 at the Philadelphia Growth Center. The author was blind to age, sex, and diagnosis while reading these films., Participants: These x-rays were taken as part of routine auxological evaluation of the normality of growth status., Main Outcome Measures: Distributions of skeletal age patterns in advance of or delayed from chronological age and frequencies of clinically significant deviant patterns are presented., Conclusions: Boys and girls with cleft palate show different maturational patterns, supporting a sex influence on the etiologies of at least some of these anomalies. Boys with unilateral cleft lip and palate and bilateral cleft lip and palate have different maturational patterns, consistent with these anomalies having different sets of etiological factors. Girls with unilateral cleft lip and palate almost always have advanced skeletal ages; whereas, boys sometimes do not. These results support the need for keeping both sex and diagnostic categories separate when conducting etiological searches.

Background: Babesia are emerging health threats to humans and animals in the United States. A collaborative effort of multiple disciplines to attain optimal health for people, animals and our environment, otherwise known as the One Health concept, was taken during a research workshop held in April 2009 to identify gaps in scientific knowledge regarding babesioses. The impetus for this analysis was the increased risk for outbreaks of bovine babesiosis, also known as Texas cattle fever, associated with the re-infestation of the U.S. by cattle fever ticks., Results: The involvement of wildlife in the ecology of cattle fever ticks jeopardizes the ability of state and federal agencies to keep the national herd free of Texas cattle fever. Similarly, there has been a progressive increase in the number of cases of human babesiosis over the past 25 years due to an increase in the white-tailed deer population. Human babesiosis due to cattle-associated Babesia divergens and Babesia divergens-like organisms have begun to appear in residents of the United States. Research needs for human and bovine babesioses were identified and are presented herein., Conclusions: The translation of this research is expected to provide veterinary and public health systems with the tools to mitigate the impact of bovine and human babesioses. However, economic, political, and social commitments are urgently required, including increased national funding for animal and human Babesia research, to prevent the re-establishment of cattle fever ticks and the increasing problem of human babesiosis in the United States.

An algorithm for analyzing changes in ECG morphology based on principal component analysis (PCA) is presented and applied to the derivation of surrogate respiratory signals from single-lead ECGs. The respiratory-induced variability of ECG features, P waves, QRS complexes, and T waves are described by the PCA. We assessed which ECG features and which principal components yielded the best surrogate for the respiratory signal. Twenty subjects performed controlled breathing for 180 s at 4, 6, 8, 10, 12, and 14 breaths per minute and normal breathing. ECG and breathing signals were recorded. Respiration was derived from the ECG by three algorithms: the PCA-based algorithm and two established algorithms, based on RR intervals and QRS amplitudes. ECG-derived respiration was compared to the recorded breathing signal by magnitude squared coherence and cross-correlation. The top ranking algorithm for both coherence and correlation was the PCA algorithm applied to QRS complexes. Coherence and correlation were significantly larger for this algorithm than the RR algorithm(p < 0.05 and p < 0.0001, respectively) but were not significantly different from the amplitude algorithm. PCA provides a novel algorithm for analysis of both respiratory and nonrespiratory related beat-to-beat changes in different ECG features.

This study assessed the interaction between cardiac beat-to-beat interval changes and systolic pressure (SP) changes. Twenty subjects breathed regularly following displayed breathing signals at 4, 6, 8, 10, 12 and 14 breaths per minute, each for 5 minutes. ECG, non-invasive blood pressure (Finapres) and respiration waveforms were recorded. Time offsets between the cyclic patterns of RR-interval and SP changes were calculated. Displayed breathing signals were well followed; the mean correlation between displayed and recorded breathing signals ranged from 0.72 to 0.86. The time offset between RR-interval peaks and subsequent SP troughs decreased with increasing respiration rate, 3.8 +/- 1.7 s, 3.5 +/- 0.7 s, 3.1 +/- 0.6 s, 2.6 +/- 0.4 s, 2.3 +/- 0.4 s and 2.0 +/- 0.4 s mean +/- SD at 4, 6, 8, 10, 12 and 14 breaths per minute respectively. The relationship between mean time offset and frequency was significant (p < 0.001), with a 95% prediction interval of +/- 0.24 s. Published data showed no relationship between time offset and frequency, with a 95% prediction interval of +/- 2.8 s. However, when the offset definition proposed in this research was applied to these data, a significant relationship (p < 0.01) was evident, with a 95% prediction interval of +/- 1.5 s. In conclusion, apparently contradictory previous findings achieve good consensus when a standardized method for presenting results is applied. A delay exists between RR-interval and blood pressure changes, and this delay varies with breathing frequency.

Baroreflex sensitivity is becoming an important clinical measurement. Nevertheless there is no recommend standard measurement protocol. This study assessed the ability of eight protocols to induce regular changes in cardiac beat-to-beat interval and systolic pressure (SP), and the effect each protocol had on baroreflex sensitivity (BRS). Twelve subjects had changes in cardiac beat-to-beat intervals and SP levels induced at 8 times a minute by following 8 different protocols, each for 3 min. These comprised breathing in a supine and standing posture, breathing through a resistance, breathing into a closed orifice (the breathing protocols), and performing handgrip exercises, being rocked, having legs raised and lowered, and being presented with mental arithmetic questions (the non-breathing protocols). Induction success of each protocol was determined by the percentage of cardiac beat-to-beat interval and SP level signals with a peak at 8 times per minute in their frequency spectra. The consistency of the induced changes was measured by a signal-to-noise ratio (SNR). BRS was calculated from the frequency spectra. The induction success was 85% for breathing and 31% for non-breathing protocols. The consistency of cardiac beat-to-beat interval changes was highest with supine breathing (SNR = 1.6 +/- 0.3) and resistance breathing (SNR = 1.5 +/- 0.5) protocols. The consistency of SP level changes was highest with resistance breathing (SNR = 1.0 +/- 0.3) and breathing into a closed orifice (SNR = 1.0 +/- 0.5) protocols. BRS values in the supine breathing protocol (24 +/- 10 ms mmHg(-1)) and the handgrip protocol (32 +/- 3 ms mmHg(-1)) were significantly greater (p < 0.05) than for standing breathing (11 +/- 5 ms mmHg(-1)), resistance breathing (17 +/- 8 ms mmHg(-1)) or breathing into a closed orifice (12 +/- 5 ms mmHg(-1)) protocols. Different protocols have different induction successes and degrees of effectiveness in inducing cardiac beat-to-beat and SP level changes. BRS is affected by the induction protocol used, highlighting the need for a standard measurement protocol.

We investigated heat tolerance and growth rate in two trials under ambient conditions in central Florida. Trial 1 (1994) involved 38 Brahman (B), 21 Senepol (S), 19 B x Angus (A), 20 S x A, and 20 Tuli (T) x A heifers. Trial 2 (1995) involved 13 A, 35 B, 30 S, 23 B x A, 17 S x A, and 28 T x A heifers. Measurements were made on three consecutive weeks during the hotter and cooler seasons of each year and included rectal temperature (RT, degrees C), respiration rate (RR, bpm), temperament score (TS; 1 = very docile, 5 = very aggressive), blood packed-cell volume (PCV), and plasma cortisol concentration (CORT). Data for RT were transformed (log10 [RT - 37]) before analysis. On the hottest date in Trial 1, log10 RT was not different between B (.39 +/- .011) and B x A (.37 +/- .016) or between T x A (.35 +/- .015) and B x A, but log10 RT was lower (P < .05) in S x A (.30 +/- .015) than in either S (.35 +/- .015) or T x A. On all dates in Trial 1, RR was lower (P < .05 to .001) and PCV was higher (P < .05 to .001) in B than in B x A. There were few differences in TS except on two dates when B scored higher (P < .01 to .001) than B x A, and these differences were associated with higher (P < .05) CORT in B than in B x A. Using initial BW as a covariate, adjusted ADG (kg) of T x A (.52 +/- .023) was not different from adjusted ADG of B x A (.57 +/- .024) or S x A (.54 +/- .023). On the hottest date in Trial 2, log10 RT and RR were higher (P < .001) in A (.59 +/- .017, 74 +/- 2.7) than in B (.47 +/- .010, 39 +/- 1.6), S (.42 +/- .011, 50 +/- 1.8), and crossbred heifers (.47 +/- .011, 60 +/- 1.8; .43 +/- .014, 55 +/- 2.4; and .50 +/- .012, 48 +/- 2.0 for T x A, S x A and B x A, respectively), and RR was higher (P < .001) in B x A than in B. On the coolest date in Trial 2, RR was slightly lower in B (32 +/- .5) than in A(34 +/- .7, P < .01) and B x A (36 +/- .6, P < .001) and was associated with higher PCV in B than in A. On both dates, TS and CORT were higher (P < .01) in B than in A. In Trial 2, adjusted ADG (kg) was higher (P < .01) in B (.43 +/- .017) than in A (.32 +/- .033), higher (P < .001) in S (.45 +/- .018) than in A, and higher (P < .001) in crossbreds (B x A [.53 +/- .023] + S x A [.44 +/- .025] + T x A [.46 +/- .019]) than in A. These data indicate that heat tolerance in F1 crosses of tropically adapted breeds (Tuli, Senepol, Brahman) with a temperate breed (Angus) is similar to heat tolerance displayed by purebred tropical breeds (Senepol, Brahman).

Two trials were conducted with heifers to determine heat tolerance among temperate Bos taurus (Angus, Hereford), Bos indicus (Brahman), tropical Bos taurus (Senepol, Romosinuano), and the reciprocal crosses of Hereford and Senepol. Differences among breeds in temperament score, circulating concentrations of cortisol, and blood packed cell volume were also investigated. Trial 1 used 43 Angus, 28 Brahman, 12 Hereford, 23 Romosinuano, 16 Senepol, 5 Hereford x Senepol (H x S), and 5 Senepol x Hereford (S x H) heifers. Trial 2 used 36 Angus, 31 Brahman, 9 Hereford, 14 Senepol, 19 H x S, and 10 S x H heifers. On the hottest summer date in Trial 1, rectal temperature of Angus was greater (P < .001) than that of Brahman, Senepol, or Romosinuano. Rectal temperature and plasma cortisol were significantly less in Senepol than in Brahman, suggesting that the differences in rectal temperature between these breeds may be due to differences in stress response possibly related to differences in temperament. Reciprocal crosses of Hereford and Senepol had rectal temperatures nearly as low as that of Senepol and displayed substantial heterosis (-9.4%, P < .05) in log10 rectal temperature on the hottest summer date. On both the hottest and coolest dates in Trial 1, Angus heifers had significantly faster respiration rates than Brahman, Romosinuano, or Senepol heifers, and Brahman had significantly slower respiration rates than Romosinuano or Senepol. On the hottest summer date in Trial 2, rectal temperature in Angus heifers was greater (P < .001) than in Brahman or Senepol had rectal temperatures similar to that of Senepol, or heterosis for log10 rectal temperature was similar to that in Trial 1 (-9.8%, P < .05). Considering rank order among breeds, Brahman always had the slowest respiration rate and greatest packed cell volume. Brahman had significantly greater temperament scores and plasma cortisol concentrations than Angus or Senepol, except that plasma cortisol was not different between Brahman and Senepol on the hottest summer date. On this date, rectal temperature did not differ between Brahman and Senepol, which supports the hypothesis that there is a relationship between response to stress and rectal temperature that helps explain differences in rectal temperature between Brahman and Senepol. The results of these trials demonstrate heat tolerance of the Senepol and Romosinuano, two Bos taurus breeds. Furthermore, the results suggest a substantial level of dominance of the Senepol's ability to maintain constant body temperature in a hot environment as measured by rectal temperature in crosses with a non-adapted breed.

Clefts of the lip and palate, separately or in combination, are among the most frequent congenital defects seen today. Their etiology is heterogeneous and may include hormonal factors, which suggest the possibility of growth effects. Whether affected children are smaller than others has not been determined. We recently showed that growth status is associated with type of cleft. We hypothesized genetic alterations in metabolic pathways that alter prenatal growth, producing clefts; some of these alterations also alter postnatal growth. Since the levels of growth-regulating hormones change during ontogeny, we expected age differences in the degree of growth deficit seen. To test this hypothesis, we examine here the cross-sectional means and distributions of standard deviation (z) scores for height and body mass indices (BMIs) for 144 children with the diagnoses unilateral cleft lip and palate (uCLP) and isolated cleft palate (iCP). We find that alteration in growth status is associated with age group as well as sex and diagnosis.

Several aspects of the relationship between maternal smoking and birth weights of infants are discussed. No satisfactory explanation for Yerushalmy's results has been given other than that low birth weight appears to relate more to the smoker than to the smoking. Recent studies by Silverman support this position. The possibility that nicotine may induce a physiologic response that serves to alleviate bioenergetic deficiency in some individuals should not be overlooked. In this view, both smoking and low birth weight are symptoms of deficient maternal bioenergetic systems.

Fifty women exposed to diethylstilbestrol (DES) in utero, 50 of their unexposed sisters (sister controls) and 43 women with abnormal Papanicolaou smears (population controls) were tested using the Diagnostic Interview Schedule to assess differences in depression and other kinds of psychologic impairment possibly associated with DES exposure. There were significant differences between DES-exposed women and their sisters in major depression and major recurrent depression. Papanicolaou controls were more depressed in comparison to sister controls. However, there were no significant differences in depression between Papanicolaou controls and the DES exposed, suggesting that major and recurrent depressions are more likely to result from concern about reproductive and other gynecologic problems than from the hormonal effects of intrauterine exposure to DES. Differences in amphetamine abuse/dependence were also noted between the DES exposed and the sister controls.

Recently, the Occupational Safety and Health Administration (OSHA) proposed regulations regarding lists of environmental substances that allegedly pose potential occupational carcinogenic risk. Known carcinogens such as bis(chloromethyl) ether, along with natural substances such as estradiol, estriol, estrone, progesterone, tannic acid, maltose, and lactose, were included in the general OSHA list. Clear distinction between true hazards and essential endogenously formed biochemicals was not made. A major reappraisal of the OSHA list is essential. The revised document should indicate the conditions under which various classes of substances constitute human health hazards -- including dosage levels and routes of entry.

Public policy affecting public health regarding effects of low-level ionizing radiations has been, and is being, determined by effects estimates based on linear or other monotonic extrapolation from high-level radiation dose-response data to presumed ecologically realistic low-level exposure effects. Such predictive, unmeasured estimates are very possibly in serious error; they are incompatible with observed low-level dose-response data that indicate a negative correlation between low-level radiation data and health effects, such as cancer mortality rates. Observed negative correlations with low-level radiation data are to be expected on the basis of evidence supporting the validity of the hormesis phenomenon. Hormesis theory, derived in part from evolutionary biology, asserts that while high levels of exposure to an agent such as ionizing radiation are indeed hazardous, ecologically realistic low levels can be stimulatory and largely beneficial. Stimulation of activities of DNA and other repair mechanisms may be involved. Although evidence of the reality of radiation hormesis has been reported in about 1000 scientific publications over the last century, this effect has been largely unrecognized. Moreover, this widespread non-acceptance of hormesis as a real-world phenomenon is usually but not always present in the case of chemical hormesis; the oversight appears systematic. The ignoring of the hormesis phenomenon seems to constitute a very serious error in modern biomedical science and in preventive medicine. A mathematical model is offered that describes the general shape of certain dose-response functions when radiation hormesis at low-level exposure is taken into consideration along with the well-known detrimental effects of high-level radiation.

Variations in moisture and substrate in preharvest corn kernels and cottonseed were linked with the ability of Aspergillus parasiticus to infect the seed and produce aflatoxin. Osmotic pressures and moisture content (MC) levels of developing starch-rich corn kernels and lipid-rich cottonseed were determined. For in vivo studies, corn kernels and cottonseed were inoculated with A. parasiticus conidia and retained on plants through maturation. For in vitro studies, samples of corn kernels and cottonseed were collected at various stages, sterilized, inoculated, incubated for 2 weeks, and assayed for toxin. Aflatoxin levels were highest in corn kernels inoculated at 28 days postflowering (52% MC) in both the in vivo and in vitro tests. Toxin concentrations in cottonseed were greatest with inoculation at 35 days postflowering (70% MC) in seed retained on the plant, but toxin accumulation continued to increase with the maturity of the seed inoculated in cottonseed used in the in vitro trials. Moisture and substrate conditions in the midrange of seed development provided optimum conditions for fungal development and toxin production in seed retained on the plant.

There is increasing evidence that blood pressure (BP) screening during adolescence may detect early evidence of hypertensive disease. Choice of instrumentation becomes important to maximize the accuracy and interpretive value of several serial readings. We therefore conducted two studies of adolescents, comparing auscultatory (Baumanometer and Random-zero), ultrasonic (Arteriosonde 1216), and infrasonic (Physiometrics SR-2) devices. These instruments were compared serially (Study 1) for older adolescents (n = 48). The Baumanometer, Arteriosonde 1216, and Physiometrics SR-2 were compared both serially and simultaneously (Study 2) for younger and older adolescents (n = 24). In both studies, the order of device presentation was completely counterbalanced. In Study 1, reliability estimates were high (r greater than 0.65), with the exception of the Arteriosonde 1216 diastolic readings, and the Physiometrics SR-2 yielded significantly lower mean diastolic BP readings than the other devices. Diastolic Phase V readings taken with the Random-zero were significantly higher when the Random-zero was presented at the end of the sequence of instrument presentation. This order of presentation effect is probably attributable to the need for overinflation when using the Random-zero device and may cause an overestimation of diastolic BP in the young. In Study 2, again the Arteriosonde 1216 did not perform reliably in recording diastolic BP. Further, the Physiometrics SR-2 device, although reliable, yielded diastolic readings significantly lower (p less than 0.001) than diastolic Phase IV readings taken both serially and simultaneously.(ABSTRACT TRUNCATED AT 250 WORDS)

This paper presents data on the extent to which blood pressure (BP) and growth status at 7 years of age are associated with BP, growth, and maturity status during adolescence. Two samples of black adolescents, namely, a representative sample (n = 562) stratified by sex and age (11 to 15 years) and a sample (n = 256) with supine BP over one standard deviation above the mean at 7 years of age (High BP7), were selected from the Philadelphia Collaborative Perinatal Project (CPP) population and followed longitudinally for 3 years. When the subjects reached adolescence we again measured supine blood pressure, height, weight, and skeletal maturity. Analyses of the data collected at 7 years of age by the CPP indicated that weight and height are highly significantly associated with systolic blood pressure (SBP) and diastolic blood pressure (DBP) respectively. Accordingly, the SBP, DBP, weights, and heights of the representative sample at age 7 were divided into percentile groupings (< 15%, 15%-85%, > 85%). Using mixed longitudinal analyses during adolescence, we found that mean SBP tracked in males through age 15 and in females through age 13 based on the percentile groupings of SBP, height, and weight. Moreover, the weight percentile groupings provided the best discrimination of SBP at these ages. Skeletal age also tracked throughout early adolescence using these percentile groupings of 7-year heights and weights. In females only, diastolic phase 4 (DBP4) during adolescence was significantly associated with 7-year height percentile groupings. In comparing the representative and the High BP7 samples at each chronological age for BP, height, weight, and skeletal age at adolescence (ages 12 to 17 years), it was found that the High BP7 sample was, on the average, taller and heavier at age 7 and throughout early adolescence. At age 17 in males, however, there were no significant differences in BP, growth, or maturity status. In females, SBP of the High BP7 sample remained significantly higher, and there was a tendency for them to remain heavier through age 17. Hence BP variation is so closely associated with growth and maturation that these factors must be taken into account when assessing BP in childhood and adolescence.

Some animal studies have shown that exposure to low levels of sulfur dioxide and dietary bisulfite is relatively harmless. To the contrary, sulfite oxidase deficiency is known in man, bisulfite is mutagenic for several test organisms, and the atmospheric SO2 level is positively correlated with death rates for several chronic diseases among some human populations. The studies reporting harmlessness for animals may be misleading because of the fallacy of typology.

This paper discusses general body growth in children with craniofacial clefts. Body growth is important in such patients because morphology reflects the cumulation of metabolism over time. The same hormones that direct general body growth also govern the ontogeny of the head and face. Body growth varies in children with different types of clefts. We found no average differences from US norms for those with isolated clefts of the lip alone or those with bilateral clefts of the lip and palate. Children with unilateral clefts of the lip and palate and with isolated cleft palate were significantly shorter than their unaffected peers. Males with these defects were also thinner than normal based on average standard deviation scores for body mass indices. Both unilateral and bilateral clefts of the lip and palate predominated in males, while isolated cleft lip was more frequent in females. Our results indicate that congenital metabolic variation contributes to the development of orofacial clefting and influences postnatal development in certain types of cleft. Accordingly, cleft type is important to growth prognosis, and growth status is relevant to optimization of therapy in orofacial cleft patients.