首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Pull-out testing of screws inserted into cement and bone under various conditions showed that the cement-screw complex was significantly stronger when the screw was placed in soft cement and the cement was allowed to polymerize without further manipulation. When screw fixation in osteoporotic bone was reinforced with cement, the bone was the weakest component in the system. Fixation under these conditions should be enhanced by increasing the area of contact between the cement and bone. By cooling the cement to prolong its working time, it could be injected with a syringe in such a way that maximum endosteal and periosteal contact was provided.  相似文献   

2.
Summary.  Acrosin activity of spermatozoa from infertile patients and fertile volunteers was measured. Acrosin activity of spermatozoa from asthenozoospermic patients and patients with unexplained infertility was lower than that from fertile volunteers. We utilize the zona-free hamster egg sperm penetration test to select candidates for conventional in vitro fertilization among unexplained infertile patients. The zona-free hamster egg sperm penetration test, however, requires several hours and special equipment which are not used in the clinical setting. It is preferable that other sperm function tests or a combination of them can replace this test. Thus three distinct tests of sperm function, namely, acrosin activity, Penetrak® test, hypo-osmotic swelling test, were compared with the hamster test, using spermatozoa from patients with unexplained infertility.
A combination of the Penetrak® test and measurement of acrosin activity could predict the results of the zona-free hamster egg sperm penetration test with 88.2% accuracy. Thus, the hamster test should be done when either Penetrak® test or measurement of acrosin activity showed abnormal values.  相似文献   

3.
This article reviews basic semen tests and new fertility tests that are providing great insights to the rapidly developing understanding of male infertility. Finally, promising new tests under development are mentioned with their potential clinical applications.  相似文献   

4.
Sperm morphology has been associated with in vitro as well as in vivo fertilisation. The study aimed to evaluate the possible relation between the percentage of spermatozoa with normal morphology and the following sperm functional assays: (i) zona-induced acrosome reaction (ZIAR); (ii) DNA integrity; (iii) chromatin condensation; (iv) sperm apoptosis; and (v) fertilisation rates. Regression analysis was employed to calculate the association between morphology and different functional tests. Normal sperm morphology correlated significantly with the percentages of live acrosome-reacted spermatozoa in the ZIAR (r = 0.518; P < 0.0001; n = 92), DNA integrity (r = -0.515; P = 0.0018; n = 34), CMA(3) -positive spermatozoa (r = -0.745; P < 0.0001; n = 92), sperm apoptosis (r = -0.395; P = 0.0206; n = 34) and necrosis (r = -0.545; P = 0.0009; n = 34). Negative correlations existed between for the acrosome reaction, and DNA integrity, while negative associations were recorded with the percentages of CMA(3) -positive spermatozoa, apoptotic and necrotic spermatozoa. Sperm morphology is related to sperm dysfunction such as poor chromatin condensation, acrosome reaction and DNA integrity. Negative and significant correlations existed between normal sperm morphology and chromatin condensation, the percentage of spermatozoa with abnormal DNA and spermatozoa with apoptotic activity. The authors do not regard sperm morphology as the only test for the diagnosis of male fertility, but sperm morphology can serve as a valuable indicator of underlying dysfunction.  相似文献   

5.
R Al-Dulymi  R Hainsworth 《Thorax》1975,30(5):566-568
Values of arterial oxygen saturation were estimated using an ear oximeter while subjects breathed a mixture of 15% oxygen in nitrogen. Results obtained from patients with lung disease were clearly separated from results obtained from normal subjects, and the lowereing of saturation was related to the clinical severity of the disease. Patients with low oximeter readings with 15% oxygen also had low levels of arterial oxygen tension during exercise.  相似文献   

6.
7.
8.
Summary Men suffering from varicocele have lower mean sperm counts and “worse” seminal parameters than those without a varicocele. Also in those with a varicocele, who already fathered a child, the mean sperm count is lower than in other fertile men. The observations, however, do not refer specifically to an existing varicocele, but are common also in other spermatogenic defects. This holds also true for the frequency of tapering forms. Besides the classical parameters of the spermatozoa also novel parameters of the extended semen analysis were tested. As well in the rate of acrosome-reacting spermatozoa, in the rate of anilinblue stained cells, in the number of zona binding-spermatozoa as in the concentration of sperm antibodies no differences between men with and men without a varicocele were found. The grade of a varicocele does not account for the degree of the spermatogenic defect. The progressive damage to the spermatogenesis by an persisting varicocele is discussed controversely. It was suggested that an early treatment of a varicocele, in particular in the adolescence, might inhibit the later insuffiency of sperm production. Correction of a varicocele is followed by an improvement of seminal parameters, in particular of sperm motility. In controlled studies, however, this effect was also observed in the untreated group. This casts some doubt on the causative effect of the varicocele treatment. The improvement of seminal parameters is not always accompanied by an increase in fertility, although also some functional parameters showed an improvement after correction of the varicocele.   相似文献   

9.
The ability of sucrose to protect spermatozoa against mitochondrial damage, artificial acrosome reaction and DNA fragmentation during ultra‐rapid cryopreservation in canine sperm was investigated. Swim‐up selected spermatozoa of second‐fraction semen were vitrified with different concentrations of sucrose (0.1, 0.25 and 0.4 m ) in proportion 1 : 1 v/v with HTF–BSA 1%. From each group, 30‐μl suspensions of cells were dropped directly into liquid nitrogen and stored for at least 24 h. Cells were thawed by submerging the spheres in HTF with 1% BSA at 37 °C. The number of progressively motile spermatozoa was significantly higher in the sucrose 0.25 m + HTF–BSA 1% (42.5 ± 2.3%, P < 0.01) than in HTF only (1.66 ± 0.3%). The same combination of sucrose 0.25 m + HTF–BSA 1% (42.7 ± 1.5%) had a stronger cryoprotective effect on the integrity of mitochondrial membrane potential (P < 0.05) and decreased the DNA fragmentation (2.8 ± 0.5%) as compared with HTF only (1.93 ± 0.6% and 5.6 ± 0.6% respectively). With respect to acrosome‐reacted spermatozoa, no significant difference was found between the groups investigated (P > 0.05). It is concluded that sucrose, a nonpermeable cryoprotectant, can effectively preserve important physiological parameters such as mitochondrial membrane potential and DNA integrity during ultra‐rapid cryopreservation.  相似文献   

10.
11.
Organophosphorus compounds are currently among the most frequently used pesticides worldwide, and therefore, the potential for human exposure to man is considerable. Their toxicity results in negative effects on many organs and systems such as the male reproductive system. So, vitamins that can offer spermatozoa protection are of great importance. This study was designed to investigate (i) the possibility of dimethoate, an organophosphate insecticide, to induce oxidative stress response in rat spermatozoa in vitro and its effect on antioxidant defence system and (ii) the role of vitamin C and vitamin E in alleviating the cytotoxic effects of dimethoate Epididymal spermatozoa were incubated for 3 h at 37 °C with different concentrations of dimethoate (50, 100 and 200 μm) without vitamins or pre-incubated with 20 mm of vitamin C or 2 mm of vitamin E. Sperm parameters, malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) levels were performed. Dimethoate caused a significant induction of oxidative damage in spermatozoa at different concentrations as evidenced by increased MDA levels. However, a significant decrease in sperm mobility, viability and activities SOD, CAT and GPx was observed. Vitamins pre-treated spermatozoa showed a significant protection against the cytotoxic effects induced by dimethoate on studied parameters.  相似文献   

12.
Semen from 88 men of infertile couples and 33 fertile donors differed in seminal fluid analysis (sperm density and motility) (SFA) as well as in the penetration of hamster ova (SPA) and bovine cervical mucus (MPT). In the fertile group, significantly more subjects had adequate SFA, SPA, or MPT results than in the infertile group. When the two groups were subdivided into those with normal or those with abnormal SFA, no differences were noted in SPA, MPT, or postcoital test (PCT) scores. The SFA parameter most consistently reflected in the results of the SPA, MPT, and PCT was sperm density. This was most evident when the SFA was poor. The worst prognosticator of fertility was the SFA, with 30% of the fertile donors having an abnormal SFA. The worst prognosticator of infertility was the MPT, with 79% of the patients penetrating in the fertile range. The SPA was a significantly better predictor than either the SFA or MPT. SPA and MPT results were positively correlated only in the overall infertile group. The SPA, MPT, and PCT measure sperm qualities distinct from those revealed by the SFA, and from each other, and in combination provide the best assessment of fertility.  相似文献   

13.
目的:探讨左旋肉碱在经皮附睾穿刺取精-卵细胞胞质内单精子注射(PESA-ICSI)治疗中的应用。方法:随机将2008年9月至2009年8月间本中心就治的79例梗阻性无精子症患者分成2组:未服药组(A组36例)和服药组(B组43例)。B组ICSI治疗取卵前3个月口服左旋肉碱(1g,2次/d)治疗,A组未作任何治疗作为对照,比较A、B两组间PESA-ICSI的获卵数、受精数、受精率、优质胚胎数和优质胚胎率。结果:A、B两组间受精数和受精率无显著性差异,但B组获得优质胚胎数及优质胚胎率明显高于A组(P<0.05)。结论:ICSI治疗前不育男性口服左旋肉碱3个月能显著提高PESA-ICSI的优质胚胎数及优质胚胎率,为将来获得良好的妊娠结局奠定基础。  相似文献   

14.
环核苷酸门控通道(CNG)是非选择性阳离子通道,直接由环核苷酸活化,是Ca2+进入细胞内的主要通道之一。CNG通道蛋白由6个不同基因编码,4个A亚单位和2个B亚单位。CNG通道受Ca2+/钙调蛋白和磷酸化/去磷酸化作用所调控。近年来,CNG通道在生殖系统方面的研究受到了广泛关注。大量研究表明,CNG通道在精子运动、获能和顶体反应中起着重要的作用。本文对CNG通道与精子功能的关系进行综述。  相似文献   

15.
Despite controversy regarding the clinical value of semen analysis, male fertility investigation still relies on a standardized analysis of the semen parameters. This is especially true for infertility clinics in both developing and developed countries. Other optional tests or sophisticated technologies have not been widely applied. The current review addresses important changes in the analysis of semen as described in the new World Health Organization (WHO) manual for semen analysis. The most important change in the manual is the use of evidence-based publications as references to determine cutoff values for normality. Apart from the above mentioned changes, the initial evaluation and handling methods remain, in most instances, the same as in previous editions. Furthermore, the review evaluates the importance of quality control in andrology with emphasis on the evaluation of sperm morphology. WHO sperm morphology training programmes for Sub-Saharan countries were initiated at Tygerberg Hospital in 1995. The external quality control programme has ensured that the majority of participants have maintained their morphological reading skills acquired during initial training. This review reports on current sperm functional tests, such as the induced acrosome reaction, and sperm-zona pellucida binding assays, as well as the impact of sperm quality in terms of DNA integrity, and the relationship of sperm function tests to sperm morphology.  相似文献   

16.

The presence of intraventricular hemorrhage (IVH) portends a worse prognosis in patients presenting with spontaneous intracerebral hemorrhage (ICH). Intraventricular hemorrhage increases the rates of hydrocephalus, ventriculitis, and long-term shunt dependence. Over the past decade, novel medical devices and protocols have emerged to directly treat IVH. Presently, we review new technological adaptations to treating intraventricular hemorrhage in an effort to focus further innovation in treating this morbid neurosurgical pathology. We summarize current and historical treatments as well as innovations in IVH including novel procedural techniques, use of the Integra Surgiscope, use of the Artemis evacuator, use of BrainPath, novel catheter technology, large bore external ventricular drains, the IRRAflow, the CerebroFlo, and the future directions of the field. Technology and medical devices for both surgical and nonsurgical methods are advancing the treatment of IVH. With many promising new technologies on the horizon, prospects for improved clinical care for IVH and its etiologies remain hopeful.

  相似文献   

17.
Tissue engineering approaches to regenerate bone stock in revision total hip replacements could enhance the longevity of the implant and benefit the quality of the patient's life. This study investigated the impaction of allograft with mesenchymal stem cells in an ovine hip hemiarthroplasty model. In total, 10 sheep were divided into two groups with 5 sheep in each group. The groups were: 1) mesenchymal stem cells mixed with allograft; 2) allograft only as a control. Ground reaction force was assessed for limb function and showed that there was no significant difference in the recovery for animals in different groups. The amount of bone regenerated around the hip replacement was assessed using un‐decalcified histology. The results showed that the stem cell group generated significantly more new bone at the implant–allograft interface and within the graft than the control group. The results from this study indicate that the use of stem cells on an allograft scaffold increases bone formation indicating that the use of stem cells for revision hip arthroplasty may be beneficial for patients undergoing revision surgery where the bone stock is compromised. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:880–885, 2008  相似文献   

18.
19.
Male accessory sex gland infections are considered to be hazards to male fertility. Various pathophysiologic concepts have evolved from experimental and clinical studies that begin to explain the effects of bacteria and immunologic events on spermatozoa. Recent studies have identified and evaluated mediators that are responsible for specific molecular processes in infections that particularly affect the function of spermatozoa.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号