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1.
To compare the effect of IV magnesium with other antihypertensives in emergency department (ED) patients with hypertension.
ED patients with a systolic BP > 135 mmHg or diastolic BP > 85 were approached for entry into the study. Those granting consent
were randomly placed into one of three treatment groups: (1) 1.5 gm IV MgSO4 (n = 42), (2) a parenteral or oral antihypertensive agent (n = 41), (3) both IV MgSO4 and an antihypertensive agent (n = 44). Systolic and diastolic blood pressures were measured at entry into the study and at 15, 30, 45, and 60 min after magnesium
or other antihypertensive medications were given. The main outcome measure was blood pressure at 60 min, and results were
compared using one-way analysis of variance with the post hoc Tukey HSD test. Compared to systolic and diastolic blood pressures
at time 0, both were lower at 15, 30, 45, and 60 min in all groups (p < 0.05). No significant difference in systolic or diastolic BP at any time point was observed when response to treatment
was compared between the three groups. Intravenous MgSO4 is as effective as antihypertensives at lowering BP in emergency department patients. 相似文献
2.
John P. McCarthy Marcas M. Bamman Janice M. Yelle Adrian D. LeBlanc Roger M. Rowe Michael C. Greenisen Stuart M. C. Lee Elisabeth R. Spector Suzanne M. Fortney 《European journal of applied physiology and occupational physiology》1997,76(1):32-40
Resistance exercise has been suggested to increase blood volume, increase the sensitivity of the carotid baroreceptor cardiac
reflex response (BARO), and decrease leg compliance, all factors that are expected to improve orthostatic tolerance. To further
test these hypotheses, cardiovascular responses to standing and to pre-syncopal limited lower body negative pressure (LBNP)
were measured in two groups of sedentary men before and after a 12-week period of either exercise (n = 10) or no exercise (control, n = 9). Resistance exercise training consisted of nine isotonic exercises, four sets of each, 3 days per week, stressing all
major muscle groups. After exercise training, leg muscle volumes increased (P < 0.05) by 4–14%, lean body mass increased (P = 0.00) by 2.0 (0.5) kg, leg compliance and BARO were not significantly altered, and the maximal LBNP tolerated without pre-syncope
was not significantly different. Supine resting heart rate was reduced (P = 0.03) without attenuating the heart rate or blood pressure responses during the stand test or LBNP. Also, blood volume
(125I and 51Cr) and red cell mass were increased (P < 0.02) by 2.8% and 3.9%, respectively. These findings indicate that intense resistance exercise increases blood volume but
does not consistently improve orthostatic tolerance.
Accepted: 17 January 1997 相似文献
3.
Data on the concentration of the elements in the human body are important, for example, to estimate the amounts required to
maintain a good healthy state or find their connections with morbidity and mortality. In this paper, the concentration of
copper (by flame atomic absorption spectrometry) in material obtained from autopsy cases of nonpoisoned people (n = 130), aged from 14 to 80 years, between 1990–2006, is presented. The following values were found (mean ± SD in micrograms
of copper per gram or per milliliter): brain 3.32 ± 1.50 (n = 43), liver 3.47 ± 1.51 (n = 79), kidney 2.15 ± 0.90 (n = 76), stomach 1.10 ± 0.76 (n = 65), intestines 1.54 ± 1.19 (n = 25), lung 1.91 ± 1.30 (n = 27), spleen 1.23 ± 0.28 (n = 3), heart 3.26 ± 0.59 (n = 5), bile 3.60 ± 1.67 (n = 13), and blood 0.85 ± 0.19 (n = 73). 相似文献
4.
Lentil root statoliths reach a stable state in microgravity 总被引:3,自引:0,他引:3
The kinetics of the movement of statoliths in gravity-perceiving root cap cells of Lens culinaris L. and the force responsible for it have been analysed under 1 g and under microgravity conditions (S/MM-03 mission of Spacehab 1996). At the beginning of the experiment in space, the amyloplasts
were grouped at the distal pole of the statocytes by a root-tip-directed 1-g centrifugal acceleration. The seedlings were then placed in microgravity for increasing periods of time (13, 29, 46 or 122 min)
and chemically fixed. During the first 29 min of microgravity there were local displacements (mean velocity: 0.154 μm min−1) of some amyloplasts (first at the front of the group and then at the rear). Nevertheless, the group of amyloplasts tended
to reconstitute. After 122 min in microgravity the bulk of amyloplasts had almost reached the proximal pole where further
movement was blocked by the nucleus. After a longer period in microgravity (4 h; experiment carried out 1994 during the IML
2 mission) the statoliths reached a stable position due to the fact that they were stopped by the nucleus. The position was
similar to that observed in roots grown continuously in microgravity. Treatment with cytochalasin D (CD) did not stop the
movement of the amyloplasts but slowed down the velocity of their displacement (0.019 μm min−1). Initial movement patterns were the same as in control roots in water. Comparisons of mean velocities of amyloplast movements
in roots in space and in inverted roots on earth showed that the force responsible for the movement in microgravity (Fc) was about 86% less (Fc = 0.016 pN) than the gravity force (Fg = 0.11 pN). Treatment with CD reduced Fc by two-thirds. The apparent viscosity of the statocyte cytoplasm was found to be 1 Pa s or 3.3 Pa s for control roots or
CD treated roots, respectively. Brownian motion or elastic forces due to endoplasmic reticulum membranes do not cause the
movement of the amyloplasts in microgravity. It is concluded that the force transporting the statoliths is caused by the actomyosin
system.
Received: 22 March 1999 / Accepted: 18 December 1999 相似文献
5.
N. J. Adams B. Pinshow L. Z. Gannes H. Biebach 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1999,169(3):195-199
We examined the relationship between body temperature (Tb) of free flying pigeons and ambient water vapor pressure and temperature. Core or near core Tb of pigeons were measured using thermistors inserted into the cloaca and connected to small transmitters mounted on the tail
feathers of free flying tippler pigeons (Columba livia). Wet and dry bulb temperatures were measured using modified transmitters mounted onto free-flying pigeons. These allowed
calculation of relative humidity and hence water vapor pressure at flight altitudes. Mean Tb during flight was 42.0 ± 1.3 °C (n = 16). Paired comparisons of a subset of this data indicated that average in-flight Tb increased significantly by 1.2 ± 0.7 °C (n = 7) over that of birds at rest (t = −4.22, P < 0.05, n = 7) within the first 15 min of takeoff. In addition, there was a small but significant increase in Tb with increasing ambient air (Ta) when individuals on replicate flights (n = 35) were considered. Inclusion of water vapor pressure into the regression model did not improve the correlation between
body temperature and ambient conditions. Flight Tb also increased a small (0.5 °C) but significant amount (t = 2.827, P < 0.05, n = 8) from the beginning to the end of a flight. The small response of Tb to changing flight conditions presumably reflects the efficiency of convection as a heat loss mechanism during sustained
regular flight. The increase in Tb on landing that occurred in some birds was a probable consequence of a sudden reduction in convective heat loss.
Accepted: 2 February 1999 相似文献
6.
Jaak Jürim?e Peter J. Abernethy B. M. Quigley Kirsten Blake Michael T. McEniery 《European journal of applied physiology and occupational physiology》1997,75(4):357-362
The purpose of this investigation was to compare the myosin heavy chain (MHC) isoform expression of the triceps brachii muscle
and isoinertial, isometric and isokinetic strength indices in competitive bodybuilders (CB, n = 5), recreational resistance trainers (RT, n = 5), endurance-trained rowers (ER, n = 5) and control (C, n = 5) subjects. Muscle tissue samples were analysed for MHC isoform content using 6% sodium dodecyl sulphate-polyacrylamide
gel electrophoresis. The CB possessed significantly smaller (P < 0.05) percentage of MHC type IIb proteins [12.92 (SD 7.08)%] than RT [30.08 (SD 6.58)%] ER [31.20 (SD 2.74)%] and C [38.22
(SD 2.95)%] groups (i.e. CB < RT ≈ ER < C). While the content of MHC type IIa isoforms did not differ significantly between
the two resistance-trained groups [CB = 55.76 (SD 5.38)%; RT = 45.72 (SD 7.8)%], CB presented significantly more type IIa
MHC isoforms than ER [42.84 (SD 2.98)%] and C [34.72 (SD 1.57)%] subjects (i.e. CB ≈ RT > ER ≈ C). The MHC type I protein
content did not differ significantly among RT [24.20 (SD 4.89)%] ER [25.38 (SD 1.67)%] and C [27.06 (SD 1.81)%] groups. The
CB [31.32 (SD 2.67)%] presented significantly more type I MHC isoforms only in comparison with RT. However, when changes in
the percentage of MHC type I isoforms were converted to effect sizes (ES), it appeared that low statistical power rather than
the absence of an effect accounted for the nonsignificant differences between CB and other groups (i.e. CB > RT ≈ ER ≈ C).
Significant differences existed in isoinertial strength among the trained athletes (i.e. CB > RT > ER ≈ C), while isometric
and isokinetic strength were not significantly different among any of the trained groups. However, the ES transformation of
data demonstrated that large differences existed between resistance-trained groups and ER for isometric and isokinetic strength
(i.e. CB ≈ RT > ER ≈ C). A statistically significant negative correlation (P < 0.001) was found between MHC type IIb isoforms and isoinertial strength index (r = − 0.68). The MHC type IIa proteins were positively related to all the strength measures considered (r = 0.51 – 0.61; P < 0.001). These data demonstrated different patterns of MHC isoform expression among the different groups of athletes and
it is suggested that these differences on occasion may affect the expression of strength.
Accepted: 24 September 1996 相似文献
7.
Data on zinc concentration in the human body may be used to interpret the results obtained in cases of chronic and acute poisonings
with zinc compounds, i.e., in clinical and forensic toxicology. In this paper, the concentrations of zinc in human tissues
and body fluids obtained from autopsy cases concerning non-poisoned people (n = 203), aged from 14 to 80 years, between 1995 and 2008, are presented. The following values were found by the flame atomic
absorption method (mean ± SD, median, range, in microgram per gram or microgram per milliliter): brain 10.3 ± 1.36, 10.2,
7.99–13.8 (n = 48); stomach 14.2 ± 3.63, 13.6, 8.00–22.5 (n = 71); intestines 15.7 ± 5.22, 15.8, 8.36–28.1 (n = 35); liver 39.6 ± 16.1, 36.6, 16.0–78.8 (n = 109); kidney 33.8 ± 10.1, 31.8, 16.4–60.9 (n = 93); lung 12.0 ± 3.88, 11.0, 6.13–18.7 (n = 26); spleen 14.7 ± 2.53, 14.6, 11.4–18.3 (n = 5); heart 26.5 ± 3.63, 26.7, 22.5–31.8 (n = 5); blood 6.81 ± 1.21, 7.00, 4.02–8.68 (n = 50); urine 0.69 ± 1.70, 0.60, 0.39–1.00 (n = 5), and bile 4.92 ± 1.64, 3.75, 3.20–7.09 (n = 9). The accuracy of the method was checked through the use of SRM Bovine Liver 1577b (certified: 127 ± 16 μg Zn/g, found:
117 ± 0.7 μg Zn/g (n = 6)). 相似文献
8.
Nigel J. Adams Berry Pinshow Leonard Z. Gannes 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1997,167(6):444-450
We used tritium-labeled water to measure total body water, water influx (which approximated oxidative water production) and
water efflux in free-flying tippler pigeons (Columba livia) during flights that lasted on average 4.2 h. At experimental air temperatures ranging from 18 to 27 °C, mean water efflux
by evaporation and excretion [6.3 ± 1.3 (SD) ml · h−1, n = 14] exceeded water influx from oxidative water and inspired air (1.4 ± 0.7 ml · h−1, n = 14), and the birds dehydrated at 4.9 ± 0.9 ml · h−1. This was not significantly different from gravimetrically measured mass loss of 6.2 ± 2.1 g · h−1 (t = 1.902, n = 14, P>0.05). This flight-induced dehydration resulted in an increase in plasma osmolality of 4.3 ± 3.0 mosmol · kg−1 · h−1 during flights of 3–4 h. At 27 °C, the increase in plasma osmolality above pre-flight levels (ΔP
osm = 7.6±4.29 mosmol · kg−1 · h−1, n = 6) was significantly higher than that at 18 °C (ΔP
osm = 0.83±2.23 mosmol · kg−1 · h−1, (t = 3.43, n = 6, P < 0.05). Post-flight haematocrit values were on average 1.1% lower than pre-flight levels, suggesting plasma expansion. Water
efflux values during free flight were within 9% of those in the one published field study (Gessaman et al. 1991), and within
the range of values for net water loss determined from mass balance during wind tunnel experiments (Biesel and Nachtigall
1987). Our net water loss rates were substantially higher than those estimated by a simulation model (Carmi et al. 1992) suggesting
some re-evaluation of the model assumptions is required.
Accepted: 8 April 1997 相似文献
9.
Kimotsuki T Niwa N Hicks MN Dunne M Cobbe SM Watanabe MA 《Journal of biological physics》2010,36(3):299-315
Roughly speaking, restitution is the dependence of recovery time of cardiac electrical activity on heart rate. Increased restitution
slope is theorized to be predictive of sudden death after heart injury such as from coronary artery occlusion (ischemia).
Adrenaline analogs are known to increase restitution slope in normal hearts, but their effects in failing hearts are unknown.
Twenty-six rabbits underwent coronary ligation (n = 15) or sham surgery (n = 11) and implantation of a lead in the heart for recording electrocardiograms. Eight weeks later, unanesthetized rabbits
were given 0.25–2.0 ml of 1 μmol/L isoprenaline intravenously, which increased heart rate. Heart rate was quantified by time
between QRS peaks (RR) and heart activity duration by R to T peak time (QTp). Ligated rabbits (n = 6) had lower ejection fraction than sham rabbits (n = 7, p < 0.0001) indicative of heart failure, but similar baseline RR (269 ± 15 vs 292 ± 23 ms, p = 0.07), QTp (104 ± 17 vs 91 ± 9 ms, p = 0.1), and isoprenaline-induced minimum RR (204 ± 11 vs 208 ± 6 ms, p = 0.4). The trajectory of QTp vs TQ plots displayed hysteresis and regions of negative slope. The slope of the positive slope
region was >1 in ligated rabbits (1.27 ± 0.66) and <1 in sham rabbits (0.35 ± 0.14, p = 0.004). The absolute value of the negative slope was greater in ligated rabbits (− 0.81 ± 0.52 vs − 0.35 ± 0.14, p = 0.04). Isoprenaline increased heart rate and slopes of restitution trajectory in failing hearts. The dynamics of restitution
trajectory may hold clues for sudden death in heart failure patients. 相似文献
10.
Kizilpinar I Civelek E Tuncer A Dogan C Karabulut E Sahiner UM Yavuz ST Sackesen C 《International journal of biometeorology》2011,55(4):623-631
Pollen plays an important role in the development and exacerbation of allergic diseases. We aimed to investigate the days
with highest counts of the most allergenic pollens and to identify the meteorological factors affecting pollen counts in the
atmosphere of Ankara, Turkey. Airborne pollen measurements were carried out from 2005 to 2008 with a Burkard volumetric 7-day
spore trap. Microscope counts were converted into atmospheric concentrations and expressed as pollen grains/m3. Meteorological parameters were obtained from the State Meteorological Service. All statistical analyses were done with pollen
counts obtained from March to October for each year. The percentages of tree, grass and weed pollens were 72.1% (n = 24,923), 12.8% (n = 4,433) and 15.1% (n = 5,219), respectively. The Pinaceae family from tree taxa (39% to 57%) and the Chenopodiaceae/Amaranthaceae family from weed taxa, contributed the highest percentage of pollen (25% to 43%), while from the grass taxa, only the Poaceae family was detected from 2005 to 2008. Poaceae and Chenopodiaceae/Amaranthaceae families, which are the most allergenic pollens, were found in high numbers from May to August in Ankara. In multiple logistic
regression analysis, wind speed (OR = 1.18, CI95% = 1.02–1.36, P = 0.023) for tree pollen, daily mean temperature (OR = 1.10, CI95% = 1.04–1.17, P = 0.001) and sunshine hours (OR = 1.15, CI95% = 1.01–1.30, P = 0.033) for grass pollen, and sunshine hours (OR = 3.79, CI95% = 1.03–13.92, P = 0.044) for weed pollen were found as significant risk factors for high pollen count. The pollen calendar and its association
with meteorological factors depend mainly on daily temperature, sunshine hours and wind speed, which may help draw the attention
of physicians and allergic patients to days with high pollen counts. 相似文献
11.
A new cultivation technique for Kappaphycus alvarezii was used in the Brazilian southeastern coast (23°02′25″ S and 43°53′39″ W), the tubular netting on floating rafts. The tubular
net technique (TN) was compared with the current method of tie–tie (TT). After 47 days, the daily growth rate (mean ± SD of TN and TT = 3.4 ± 0.7% day−1), carrageenan yield (mean ± SD of TN and TT = 36 ± 1.3%), gel strength (mean ± SD of TN and TT = 730 ± 114.5 g cm2), and
viscosity (mean ± SD of TN and TT = 350 ± 60.4 cP) did not differ between the two techniques (p > 0.05). The amount of time used to plant (TT = 30.2 ± 2.3 min and TN = 13.3 ± 3.4 min) and to harvest the seedlings (TT = 36.2 ± 2.7 min
and TN = 17.8 ± 3.7 min) were lower in TN (p < 0.001). It is concluded that TN was more effective than TT, the cultivation management (time rates used to plant and harvest
the seedlings) was 53.6% faster, no seedlings were lost, the cost was lower, and an estimated return in 1 year of nearly 20%
more than that of the TT technique. 相似文献
12.
The major purpose of this spaceflight project was to investigate the starch-statolith hypothesis for gravity perception,
and a secondary goal was to study plant growth and development under spaceflight conditions. This research was based on our
ground studies of gravity perception in the wild type and three starch-deficient (one starchless and two reduced starch) mutants
of Arabidopsis thaliana (L.) Heynh. Dark-grown seedlings that developed in microgravity were given one of several (30 min, 60 min, or 90 min) 1-g stimuli by an on-board centrifuge, and additional controls for seedling development also were performed. These latter control
experiments included a morphological study of plants that developed in space in microgravity (F μg), in space on a centrifuge (F 1g), on the ground (G 1g), and on a rotating clinostat on the ground. Since elevated levels of ethylene were reported in the spacecraft atmosphere,
additional controls for morphology and gravitropism with added ethylene also were performed. While exogenous ethylene reduced
the absolute magnitude of the response in all four strains of Arabidopsis, this gas did not appear to change the relative graviresponsiveness among the strains. The relative response of hypocotyls
of microgravity-grown seedlings to the stimuli provided by the in-flight centrifuge was: wild type > starch-deficient mutants.
Although the protoplast pressure model for gravity perception cannot be excluded, these results are consistent with a statolith-based
model for perception in plants.
Received: 12 February 1999 / Accepted: 9 March 1999 相似文献
13.
Christof Janko Stefan Linke Thomas Romig Dorothea Thoma Wolfgang Schröder Andreas König 《European Journal of Wildlife Research》2011,57(5):1033-1042
This study investigated the epidemiological and ecological factors to assess the infection pressure of alveolar echinococcosis
to human which are living in villages and small towns. Foxes and fox faeces were examined for Echinococcus multilocularis and foxes were observed by radio telemetry in Upper Bavaria, Germany. Forty-three percent of the village foxes (n = 65) had been infected with E. multilocularis. This prevalence rate did not differ significantly from the prevalence among rural foxes, which was 39% (n = 33; χ
2 = 0.12, df = 1, p = 0.727) determined by the intestinal scraping technique. PCR analyses of fox faeces showed a higher infection rate of 35%
(n = 26) among rural foxes than among foxes in villages and small towns (26%, n = 69; χ
2 = 0.68, df = 1, p = 0.411). One quarter of the fox faecal samples come from private gardens of residents. The radio-tracking study on 17 foxes
showed that foxes preferred the built-up area and grassland outside the villages. Village foxes concentrated their activity
within a range of 500 m around the settlement. Sixty-four percent of all bearings for radio-tracked foxes showed positions
in areas outside the town, and 36% of bearings were within the settlement. Village foxes, which are infected with E. multilocularis, are able to carry the parasite continuously into settlements and fox faeces present an immediate source of infection to
humans, especially within their gardens. Therefore, foxes are responsible for environmental E. multilocularis egg contamination in the vicinity of humans, leading to an infection risk to inhabitants of villages and small towns. 相似文献
14.
15.
Nigel A. S. Taylor Mark J. Patterson James D. Cotter Duncan J. Macfarlane 《European journal of applied physiology and occupational physiology》1997,76(4):380-386
The influence of artificially induced anaemia on thermal strain was evaluated in trained males. Heat stress trials (38.6°C,
water vapour pressure 2.74 kPa) performed at the same absolute work rates [20 min of seated rest, 20 min of cycling at 30%
peak aerobic power (V˙O2peak), and 20 min cycling at 45% V˙O2peak] were completed before (HST1) and 3–5 days after 3 units of whole blood were withdrawn (HST2). Mild anaemia did not elevate
thermal strain between trials, with auditory canal temperatures terminating at 38.5°C [(0.16), HST1] and 38.6°C [(0.13), HST2;
P > 0.05]. Given that blood withdrawal reduced aerobic power by 16%, this observation deviates from the close association often
observed between core temperature and relative exercise intensity. During HST2, the absolute and integrated forearm sweat
rate (m˙
sw) exceeded control levels during exercise (P < 0.05), while a suppression of forehead m˙
sw occurred (P < 0.05). These observations are consistent with a possible peripheral redistribution of sweat secretion. It was concluded
that this level of artificially induced anaemia did not impact upon heat strain during a 60-min heat stress test.
Accepted: 17 April 1997 相似文献
16.
Axelsson M Thorarensen H Nilsson S Farrell AP 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2000,170(2):145-152
Cardiac output, blood flow to the coeliac and mesenteric arteries, dorsal aortic blood pressure and heart rate were recorded
simultaneously at rest and postprandial for 6 days in a teleost, the red Irish lord (Hemilepidotus hemilepidotus). We anticipated that gastrointestinal blood flow would increase postprandially, supported by an increase in cardiac output.
However, we had no predictions for either the exact time-course of this response, or for the regional distribution of blood
flow between to the two major arteries comprising the splanchnic circulation. In resting, unfed animals, blood flow to the
coeliac artery and mesenteric artery was 4.1 ± 0.6 ml min−1 kg−1 and 4.9 ± 1.3 ml min−1 kg−1, respectively (mean ± SEM, n=7), which together represented 34% of cardiac output. Feeding increased blood flow to the coeliac and mesenteric arteries
in a time-dependent manner. The increase in coeliac artery blood flow preceded that in the mesenteric artery, a finding that
is consistent with the coeliac artery supplying blood to the liver and stomach, while the mesenteric artery supplies blood
to the stomach and intestine. Coeliac blood flow had increased by 84 ± 18% after 1 day and had a peak increase of 112 ± 40%
at day 4 postprandial. Mesenteric blood flow was not significantly elevated at day 1, but had increased by 94 ± 19% at day 4
postprandial. Cardiac output also increased progressively, increasing by a maximum of 90 ± 30% at day 4. Because the increase
in cardiac output was adequate to meet the postprandial increase in gut blood flow, the postprandial decreases in vascular
resistance for the coeliac and mesenteric circulations mirrored the increases in blood flow. Intra-arterial injections of
adrenaline and noradrenaline into resting fish more than doubled coeliac and mesenteric vascular resistances, and blood flow
decreased proportionately. This adrenergic vasoconstriction was totally abolished by pretreatment with the α-adrenoceptor
antagonist phentolamine, which in itself approximately halved coeliac and mesenteric vascular resistances. These observations
indicate a significant α-adrenergic tone in the gastrointestinal circulation of the red Irish lord, the loss of which could
not entirely account for the postprandial increase in gastrointestinal blood flow. Other control mechanisms are suggested.
Accepted: 17 November 1999 相似文献
17.
Megakaryopoiesis is largely disturbed in myelodysplastic syndromes (MDS), and megakaryocytes (MKs) frequently show multinucleation.
Here, we investigated dysplastic mono-, bi-, and multinuclear MKs (n = 169) of seven patients with MDS and one patient with myelodysplastic/myeloproliferative neoplasm by sequential multilocus
FISH. Analysis of binuclear MKs with a combined DNA content of 4 N (n = 46) indicated a significantly even (symmetric) chromosome distribution between the two separate nuclei (p = 0.0223), which suggests bipolar spindle orientation and symmetric chromosome segregation during the first endomitotic cell
cycle. In contrast, multinuclear MKs of higher ploidy (>4 N, n = 108) demonstrated a significantly uneven (asymmetric) chromosome distribution between the separate nuclei (p = 0.0248). Thus, the internuclear chromosomal distribution of dysplastic MKs depends on the level of ploidy. In addition,
centrosomal aberrations were not found in dysplastic MKs. Our results indicate that megakaryocytic multinucleation in MDS
originates from dysregulated endomitosis, including restoration of karyokinesis. 相似文献
18.
Ute Meister 《Mycotoxin Research》2009,25(3):133-139
Over a period of 8 years (2000–2007), wheat (n = 407) and rye (n = 510) samples of integrated and organic cultivation in the Federal State of Brandenburg were analyzed by HPLC for the Fusarium toxins deoxynivalenol (DON) and zearalenone (ZEA). In the years 2002 and 2007, the overall contamination level was higher
than in the other years. The percentage of DON-positives (>50 μg/kg) varied from 5 to 86%, the median and maximum levels varied
from 50 to 380 μg/kg and from 50 to 10,400 μg/kg, respectively. The percentage of ZEA-positives (>3 μg/kg) varied from 2
to 41%, the median and maximum levels varied from 8 to 84 μg/kg and from 10 to 451 μg/kg. In the 8 years of testing, frequency
and levels of DON and ZEA were significantly lower in cereals of organic cultivation compared with cereals of integrated cultivation. 相似文献
19.
K. E. Deaton C. M. Bishop P. J. Butler 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1997,167(5):319-327
The role of thyroid hormones in the development of the locomotor and cardiac muscles of the barnacle goose (Branta leucopsis) was investigated. From 2 weeks of age, goslings were treated with thyroxine, triiodothyronine, or methimazole (a thyroid
inhibitor). Birds were killed at 6 weeks (n = 5) or 9 weeks (n = 4) and various locomotor and cardiac muscle masses recorded and tissue samples taken for analysis of citrate synthase activity.
The effects of thyroxine and triiodothyronine were not significantly different from each other, except in the case of the
iliofibularis at 9 weeks. The mass-specific citrate synthase activity of the iliofibularis, semimembranosus muscles and liver
were significantly increased by thyroid hormone treatment. Cardiac muscle showed a significant hypertrophy at 9 weeks of age
following treatment with thyroxine. Hypothyroidism induced by treatment with methimazole exhibited the greatest effect on
the pectoralis muscle, reducing citrate synthase activity by 33%. Mass-specific citrate synthase activity of the pectoralis
and pectoralis mass (% body wt.) were found to be highly correlated (r
2 = 0.74) at 6 weeks of age. It is suggested that thyroid hormones may be involved in controlling the tissue-specific timing
of the maturation of locomotor and cardiac muscles.
Accepted: 16 September 1996 相似文献
20.
One hundred sixty-four adult male volunteers (29 controls [Group 1] and 135 combi drivers) enrolled in the study. The combi
drivers were divided into three groups as nonusers of either Maras powder or cigarette (Group 2), smokers (Group 3), and users of Maras powder (Group 4). Blood lead levels (BLLs) were analyzed by
atomic absorption spectrophotometer. BLL was detected as 2.8 ± 2.3 μg/dL in Group 1 (n = 29); however, it was 3.5 ± 1.6 μg/dL in Group 2 (n = 33), 3.8 ± 2.4 μg/dL in Group 3 (n = 62), and 3.9 ± 2.4 μg/dL in Group 4 (n = 40). BLL in Group 1 was found significantly lower than other groups (p < 0.05). The use of cigarette or Maras powder by the drivers did not give rise to a marked difference on the BLLs (p > 0.05). BLL of (combi) drivers was detected to be significantly higher than nondrivers; however, it was still under the
hazardous level of 10 μg/dL announced by WHO. Although there are publications reporting that usage of tobacco increases the
level of lead in blood, both smoking and use of Maras powder did not affect BLL markedly in our study.
Poster presented (the abstract section published in Congress Book) at the 7th Congress of Turkish Family Physicians, 23–26
May 2006, Cesme-IZMIR, Turkey. 相似文献