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排序方式: 共有628条查询结果,搜索用时 15 毫秒
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Evaluation of three substitutes for Percoll in sperm isolation by density gradient centrifugation 总被引:9,自引:4,他引:9
Silane-coated silica particle solutions (ISolate(TM) and PureSperm)TM)) and
iodixanol (OptiPrep(TM)) were compared to polyvinylpyrrolidone (PVP)-coated
silica particles (Percoll(TM)) in their efficacy to recover spermatozoa by
gradient centrifugation for use in assisted reproductive procedures.
Efficacy was assessed in terms of percentages of sperm recovery, sperm
vitality and motility, normal sperm morphology and normal sperm chromatin
condensation. No significant difference was found in the recovery of
spermatozoa for men with both normal sperm counts and oligozoospermia,
between PVP-coated and silane-coated particle solutions. Iodixanol had
significantly lower sperm recovery compared to the other products. Sperm
vitality, progressive motility, normal morphology and normal chromatin
condensation did not differ significantly between any of the sperm
isolation products.
相似文献
5.
Mutation spectrum and genotype-phenotype analyses in Cowden disease and Bannayan-Zonana syndrome, two hamartoma syndromes with germline PTEN mutation 总被引:22,自引:1,他引:22
Marsh DJ; Coulon V; Lunetta KL; Rocca-Serra P; Dahia PL; Zheng Z; Liaw D; Caron S; Duboue B; Lin AY; Richardson AL; Bonnetblanc JM; Bressieux JM; Cabarrot-Moreau A; Chompret A; Demange L; Eeles RA; Yahanda AM; Fearon ER; Fricker JP; Gorlin RJ; Hodgson SV; Huson S; Lacombe D; Eng C 《Human molecular genetics》1998,7(3):507-515
The tumour suppressor gene PTEN , which maps to 10q23.3 and encodes a 403
amino acid dual specificity phosphatase (protein tyrosine phosphatase;
PTPase), was shown recently to play a broad role in human malignancy.
Somatic PTEN deletions and mutations were observed in sporadic breast,
brain, prostate and kidney cancer cell lines and in several primary tumours
such as endometrial carcinomas, malignant melanoma and thyroid tumours. In
addition, PTEN was identified as the susceptibility gene for two hamartoma
syndromes: Cowden disease (CD; MIM 158350) and Bannayan-Zonana (BZS) or
Ruvalcaba-Riley-Smith syndrome (MIM 153480). Constitutive DNA from 37 CD
families and seven BZS families was screened for germline PTEN mutations.
PTEN mutations were identified in 30 of 37 (81%) CD families, including
missense and nonsense point mutations, deletions, insertions, a
deletion/insertion and splice site mutations. These mutations were
scattered over the entire length of PTEN , with the exception of the first,
fourth and last exons. A 'hot spot' for PTEN mutation in CD was identified
in exon 5 that contains the PTPase core motif, with 13 of 30 (43%) CD
mutations identified in this exon. Seven of 30 (23%) were within the core
motif, the majority (five of seven) of which were missense mutations,
possibly pointing to the functional significance of this region. Germline
PTEN mutations were identified in four of seven (57%) BZS families studied.
Interestingly, none of these mutations was observed in the PTPase core
motif. It is also worthy of note that a single nonsense point mutation,
R233X, was observed in the germline DNA from two unrelated CD families and
one BZS family. Genotype-phenotype studies were not performed on this small
group of BZS families. However, genotype-phenotype analysis inthe group of
CD families revealed two possible associations worthy of follow-up in
independent analyses. The first was an association noted in the group of CD
families with breast disease. A correlation was observed between the
presence/absence of a PTEN mutation and the type of breast involvement
(unaffected versus benign versus malignant). Specifically and more
directly, an association was also observed between the presence of a PTEN
mutation and malignant breast disease. Secondly, there appeared to be an
interdependent association between mutations upstream and within the PTPase
core motif, the core motif containing the majority of missense mutations,
and the involvement of all major organ systems (central nervous system,
thyroid, breast, skin and gastrointestinal tract). However, these
observations would need to be confirmed by studying a larger number of CD
families.
相似文献
6.
A. A. H. P. Megens J. Voeten J. Rombouts T. F. Meert C. J. E. Niemegeers 《Psychopharmacology》1987,93(3):382-388
Spontaneous and drug-induced (haloperidol, apomorphine, and amphetamine) motor activity of rats was measured simultaneously via two distinct and independent methods: the classical optical scanning technique and a new procedure based on the piezo-electric principle. The latter procedure measured animal-induced mechanical vibrations of a flexible cage floor which were transduced into electric signals via piezo-electricity. The piezo method appeared to be relatively more sensitive in recording the small, stereotyped motor movements induced by apomorpine (0.63–10 mg/kg) and high doses of amphetamine (2.5–20 mg/kg). The optical scanning technique, on the other hand, was more sensitive in recording horizontal displacements across the cage such as induced by low doses of amphetamine (0.31–2.5 mg/kg). Both methods showed comparable sensitivity in recording the depression of behaviour induced by haloperidol (0.04–1.25 mg/kg) or low doses of apomorphine (0.04–0.16 mg/kg). The piezo method may complement the optical scanning procedure, and thereby enhance the information on the extent that test compounds modify animal behaviour. 相似文献
7.
We report our clinical experience with phototherapy in 3802 infants; 3629 were exposed to "standard" daylight phototherapy and 173 to "high-intensity" blue-light phototherapy. High-intensity blue-light phototherapy was twice as effective as standard daylight phototherapy in decreasing bilirubin concentrations. No failures occurred with high-intensity phototherapy compared with an overall failure rate of 1.84/1000 with daylight lamps; these cases were transferred to high-intensity phototherapy with prompt response. Rebound after cessation of phototherapy was greater in those exposed to high-intensity blue light with a significantly greater number requiring a second exposure. However, the incidence was still low. No third exposure was required in any infant. Nursing of infants under high-intensity blue light was more difficult and inconvenient as was clinical monitoring. The light also caused more stress on the nursing and medical personnel. However, the infants tolerated both types of phototherapy equally well. High-intensity blue-light phototherapy would seem to be the treatment of choice for infants with rapidly increasing or very high bilirubin levels, as well as in those not responding adequately to daylight phototherapy. 相似文献
8.
T Berghmans A P Meert C Mascaux M Paesmans J J Lafitte J P Sculier 《Annals of oncology》2003,14(5):715-721
BACKGROUND: Citation factors are applied to assess scientific work despite the fact that they were developed commercially in order to compare competing journals. The aim of the present study was to determine whether there is a relationship between citation factors and a trial's methodological quality using published randomised trials in lung cancer clinical research. Material and methods All of the randomised trials included in nine systematic reviews performed by the European Lung Cancer Working Party (ELCWP) were assessed using two quality scales (Chalmers and ELCWP). RESULTS: One hundred and eighty-one articles were eligible. The median overall ELCWP and Chalmers quality scores were 61.8% and 49.0%, respectively, with a correlation coefficient (r(s)) of 0.74 (P <0.001). A weak association was observed between citation factors and quality scores with the respective correlation coefficients ranging from 0.18 to 0.40 (ELCWP scale) and from 0.21 to 0.38 (Chalmers scale). American authors published trials significantly more often in journals with high citation factors than European or non-American authors (P <0.0001), despite no better methodological quality. Positive trials, which were significantly more likely to be published in journals with higher citation factors, were of no better quality than negative ones. CONCLUSION: Journals with higher citation factors do not appear to publish clinical trials with higher levels of methodological quality, at least for trials in the field of lung cancer research. 相似文献
9.
Abstract: We report the first case of fatal anthrax meningoencephalitis in Hong Kong over the past 60 years. A 13 year-old boy presented with right lower quadrant pain, diarrhoea and progressive headache. Lumbar puncture yielded gram positive bacilli initially thought to be Bacillus cereus, a contaminant. He was treated with ampicillin and cefotaxime, but died 3 days after hospitalization. The organism isolated from blood and cerebrospinal fluid was later identified as Bacillus anthracis. 相似文献
10.
To report our clinical experience on the use of oral erythromycin for the treatment of severe gastrointestinal dysmotility in preterm infants.
A case series study of seven preterm infants (six were very low birthweight) with severe intestinal dysmotility in a tertiary neonatal centre.
All responded favourably without adverse effects and tolerated full enteral feeding within 1–2 weeks of the commencement of the drug.
As prolonged total parenteral nutrition carries significant risk of complications, this therapy could be considered in selected preterm infants who fail to establish enteral feeding after an extended period, and in whom an anatomically obstructive lesion of the gastrointestinal tract has been excluded. Meanwhile, we would caution against the widespread implementation of this therapeutic approach until formal evaluation by randomized controlled trials have established the exact role of erythromycin, or its analogues, in the treatment of intestinal dysmotility in preterm infants. 相似文献
Methodology:
A case series study of seven preterm infants (six were very low birthweight) with severe intestinal dysmotility in a tertiary neonatal centre.
Results:
All responded favourably without adverse effects and tolerated full enteral feeding within 1–2 weeks of the commencement of the drug.
Conclusions:
As prolonged total parenteral nutrition carries significant risk of complications, this therapy could be considered in selected preterm infants who fail to establish enteral feeding after an extended period, and in whom an anatomically obstructive lesion of the gastrointestinal tract has been excluded. Meanwhile, we would caution against the widespread implementation of this therapeutic approach until formal evaluation by randomized controlled trials have established the exact role of erythromycin, or its analogues, in the treatment of intestinal dysmotility in preterm infants. 相似文献