BACKGROUND: Patients who have a first episode of venous thromboembolism in the absence of known risk factors for thrombosis (idiopathic thrombosis) are often treated with anticoagulant therapy for three months. Such patients may benefit from longer treatment, however, because they appear to have an increased risk of recurrence after anticoagulant therapy is stopped. METHODS: In this double-blind study, we randomly assigned patients who had completed 3 months of anticoagulant therapy for a first episode of idiopathic venous thromboembolism to continue receiving warfarin, with the dose adjusted to achieve an international normalized ratio of 2.0 to 3.0, or to receive placebo for a further 24 months. Our goal was to determine the effects of extended anticoagulant therapy on rates of recurrent symptomatic venous thromboembolism and bleeding. RESULTS: A prespecified interim analysis of efficacy led to the early termination of the trial after 162 patients had been enrolled and followed for an average of 10 months. Of 83 patients assigned to continue to receive placebo, 17 had a recurrent episode of venous thromboembolism (27.4 percent per patient-year), as compared with 1 of 79 patients assigned to receive warfarin (1.3 percent per patient-year, P<0.001). Warfarin resulted in a 95 percent reduction in the risk of recurrent venous thromboembolism (95 percent confidence interval, 63 to 99 percent). Three patients assigned to the warfarin group had nonfatal major bleeding (two had gastrointestinal bleeding and one genitourinary bleeding), as compared with none of those assigned to the placebo group (3.8 vs. 0 percent per patient-year, P=0.09). CONCLUSIONS: Patients with a first episode of idiopathic venous thromboembolism should be treated with anticoagulant agents for longer than three months. 相似文献
Preliminary data have suggested that female infertility due to corpus
luteum insufficiency may be caused by subclinical hypothyroidism
[exaggerated thyroid-stimulating hormone (TSH) response to thyrotrophin-
releasing hormone (TRH) stimulation]. L-Thyroxine supplementation has been
recommended to achieve pregnancies in subclinical hypothyroid women. This
controlled study was carried out in order to investigate the biochemical
diagnosis of subclinical hypothyroidism as a possible infertility factor.
Five infertile patients (aged 25-36 years) with subclinical hypothyroidism
(n = 4, stimulated TSH >20 microU/ml) or primary hypothyroidism (n = 1)
and five healthy controls (aged 22-39 years) with normal thyroid function
(stimulated TSH <15 microU/ml), regular cycles and no history of
infertility were studied in the early follicular phase. In the pre-study
evaluation, eight of 23 volunteers (34.8%) had to be excluded because of
subclinical hypothyroidism with stimulated TSH values (TSHs) >15
microU/ml. Cycle function of patients and controls was compared by the
method of LH pulse pattern analysis. Therefore blood samples were drawn
every 10 min during a 24 h period. Sleep was recorded from midnight to 7
a.m. Repetition of the TRH tests at the end of the 24 h blood sampling
period confirmed the difference in stimulated TSH values of the two study
groups. Pulse analysis for luteinizing hormone (LH), TSH and prolactin
showed no differences between patients and controls for pulse frequency,
amplitude, height, length, area under curve (AUC) and the 24 h mean. Even
the hypothyroid patient had a normal LH pulse pattern. Additional
measurement of melatonin in pooled sera every 30 min gave the
well-documented diurnal profiles during day and night for both groups.
Patients had significantly higher melatonin values at seven time points
during the night. Peaks for LH, TSH, prolactin and cortisol were correlated
with the sleep stages wake, rapid eye movement, 1 + 2 and 3 + 4. We
concluded that corpus luteum insufficiency in female infertility cannot be
explained by subclinical hypothyroidism and thus should not be treated with
L-thyroxine for fertility reasons.
相似文献
1. The general characteristics and Na and K movements of L cells (derived from mouse epithelium) have been measured. Both cells grown in suspension (LS cells) and as a monolayer (L cells) were used.2. The volume of L cells was 1.2 x 10(-9) cm(3) and of LS cells 3.5 x 10(-9) cm(3); of this 82% was water.3. Electron micrographs showed the presence of numerous protrusions (filopodia) from both forms of the cell. These had the effect of increasing the surface area of the cell by 2-4 times over smooth cells of the same volume. On changing from the flattened to the spherical shape during trypsinization, the filopodia altered to maintain a constant V/A ratio.4. These cells contain K, about 170 m-mole/l. intracellular water and Na, 9 m-mole/l. intracellular water (L cells only) at 20 degrees C. The K fluxes are 1.9 p-mole/cm(2) sec for LS cells and 0.8 p-mole/cm(2) sec for L cells and the Na fluxes are 1.8 p-mole/cm(2) sec for L cells (expressed as per total cell surface (including filopodia)). If expressed as p-mole/cell per sec then L and LS cells have the same K flux.5. 10(-4)M ouabain reduces the K influx to half, indicating an insensitivity to the glycosides common to the species. In the prolonged presence of ouabain the cells come into a new steady state with a [K](1), of 140 and a [Na](1) of 20-30 m-mole/l. intracellular water, but a constant [Na + K](1).6. Both DNP (10(-3)M) and IAA (10(-4)M) are required for maximum inhibition of K uptake, as both aerobic and anaerobic metabolic pathways may be used to drive the pump.7. K removal decreases the Na efflux, and Na removal (eventually) decreases the K influx providing evidence for Na/K coupling.8. The cells contain 7.5 m-mole/litre intracellular water of ATP, a level some 15 times that of ADP.9. The Na pump in these cells is very similar to that found in other tissues in that (a) it requires K to work, (b) it is blocked by ouabain and metabolic inhibitors and (c) it transports three molecules of Na for each two molecules of K. 相似文献
The development of the ventral papillae ofNotocotylus triserialis was studied by light and electron microscopy. The median row papillae first appeared on 2-day-old worms and the lateral rows on 4-day-old worms. The papillae grew in size and in number and size of constituent cells, with rapid development occurring between days 5 and 8. This rapid growth corresponded with the time of onset of egg production by the worm.Electron microscopy indicated that the papillae of 3- and 4-day-old worms contained numerous undifferentiated cells with little cytoplasm and extensive Golgi bodies. By days 5 and 6 most of these cells contained developing mitochondria; only a few undifferentiated cells were visible. Muscles and nervous tissue also became more prominent at this time. The ultrastructure of the papillae of 7-and 8-day-old worms was similar to that of papillae from adult worms. After day 9 or 10, the size and number of cells per papilla remained constant until the death of the worm. 相似文献
The aims of this work were to measure the accuracy of one continuous speech recognition product and dependence on the speaker's
gender and status as a native or nonnative English speaker, and evaluate the product's potential for routine use in transcribing
radiology reports. IBM MedSpeak/Radiology software, version 1.1 was evaluated by 6 speakers. Two were nonnative English speakers,
and 3 were men. Each speaker dictated a set of 12 reports. The reports included neurologic and body imaging examinations performed
with 6 different modalities. The dictated and original report texts were compared, and error rates for overall, significant,
and subtle significant errors were computed. Error rate dependence on modality, native English speaker status, and gender
were evaluated by performing ttests. The overall error rate was 10.3 +/- 3.3%. No difference in accuracy between men and women
was found; however, significant differences were seen for overall and significant errors when comparing native and nonnative
English speakers (P = .009 and P = .008, respectively). The speech recognition software is approximately 90% accurate, and
while practical implementation issues (rather than accuracy) currently limit routine use of this product throughout a radiology
practice, application in niche areas such as the emergency room currently is being pursued. This methodology provides a convenient
way to compare the initial accuracy of different speech recognition products, and changes in accuracy over time, in a detailed
and sensitive manner. 相似文献
This article reviews major risk factors for cigarette smoking, alcohol, and other drug abuse and promising community-based approaches to primary prevention. In a longitudinal experimental study, 8 representative Kansas City communities were assigned randomly to program (school, parent, mass media, and community organization) and control (mass media and community organization only) conditions. Programs were delivered at either 6th or 7th grade, and panels were followed through Grade 9 or 10. The primary findings were (a) significant reductions at 3 years in tobacco and marijuana use and (b) equivalent reductions for youth at different levels of risk. This study provides evidence that a comprehensive community program-based approach can prevent the onset of substance abuse and that the benefits are experienced equally by youth at high and low risk. 相似文献
Sex differences in mate preferences are well established. It is also well understood that humans often seek to manipulate their standing on important mate-value traits. Yet, there is a paucity of work examining potential sex differences in response to deception along these important dimensions. In Study 1, a sample of 280 undergraduates (123 females) responded to a hypothetical online dating scenario asking participants to rank how upset they would be if deceived about a date’s attractiveness, occupation, or volunteerism. Women ranked occupation deception as more upsetting than men did, and men ranked attractiveness deception as more upsetting than women did. Given potential measurement differences between forced-choice and continuous response options, Study 2 randomly assigned 364 undergraduates (188 females) to one of the deceptions conditions and asked them to report their level of upset and willingness to go on the date using a continuous response scale. Women were more likely than men to cancel the date if the deception involved volunteerism or occupation. There was no significant sex difference in the attractiveness condition. Neither mate value nor sociosexuality moderated the sex difference in the levels of upset due to the deception. Together, these findings demonstrate that women and men exhibit differences in the degree to which they become upset by opposite sex deceptions in online dating, regardless of self-perceived mate value and sociosexuality, in alignment with evolved sex differences in mate preferences.