Technical aspects of oocyte cryopreservation

Since the successful development in the mouse, the oocyte cryopreservation has been applied with varying success to a number of different species including the human. The recently reported successes in terms of pregnancies obtained by human oocyte cryopreservation are encouraging. Several studies typically reported different rates of survival (20-80%), fertilization (30-60%) and cleavage (32-100%). This variability of results throws some doubts on the usefulness of oocyte cryopreservation in IVF treatment cycles. It remains to be determined whether the relatively different success rates reported in literature, mainly in terms of survival rate, are due to methodological differences. We tried to investigate the effect of some factors on the oocyte survival rate after thawing: the presence or absence of cumulus oophorus and the exposure time of the oocytes to cryoprotectant. We suggest that a combination of several factors including both morphological and biophisical ones can affect the oocyte survival rate.     

Clinical applications of SPECT

The clinical use of single photon emission computed tomography (SPECT) has grown steadily over the last decade. SPECT is now an essential technique for certain studies such as cerebral blood flow imaging. Many other common nuclear medicine studies give better results when they are performed with SPECT. These include myocardial perfusion imaging with thallium-201 or the new technetium-99m perfusion agents, myocardial infarct imaging with infarct-avid agents, imaging of tumors or infections with agents such as gallium-67 or indium-111 WBC's, and certain cases of bone imaging. Still other studies such as liver/spleen imaging, most brain studies, and perhaps renal imaging may benefit from SPECT even though planar imaging gives satisfactory results. Future developments in 3D display techniques and faster computers may extend the clinical usefulness of SPECT to other areas such as pulmonary perfusion imaging and gated cardiac blood pool imaging.Abbreviations SPECT single photon emission computed tomography - WBC white blood cells - 3D three dimensional     

Clinical applications of BSM

Body surface mapping (BSM) has now become a feasible clinical technique, providing useful information applicable to the diagnosis of cardiac arrhythmias and their treatment by surgical and endocardial catheter ablation. In WPW patients, validation of preexcitation patterns has been obtained by computer simulation and by direct epicardial mapping at surgery. BSM pacemapping has subsequently been developed to be used during radiofrequency catheter ablation. This method has been evaluated prospectively and its predictive accuracy assessed. The recognition of two distinct BSM patterns in idiopathic ventricular tachycardia, has led to the application of successful pacemapping for radiofrequency catheter ablation. The use of a realistic tridimensional heart-torso computer model has shown that specific sites of endocardial stimulation are related to distinct thoracic map patterns.     

Effects of cryopreservation on meiotic spindles of oocytes and its dynamics after thawing: clinical implications in oocyte freezing--a review article

Embryo freezing has been a successful practice, but oocyte cryopreservation formerly achieved poorer results. This was mainly due to low rates of survival, fertilization, and development. The major dissimilarities for oocytes to embryos are the character of the plasma membrane, the presence of cortical granules, at the metaphase of meiosis II with the spindle system. In addition, the oocytes must be fertilized by sperm at the appropriate time. To improve the survival rate, a refined slow freezing method with increased sucrose concentration would dehydrate oocytes more sufficiently. Vitrification is another approach to prevent ice crystal formation. Intracytoplasmic sperm injection is used to overcome possible zona hardening from the release of cortical granules. The microtubules of meiotic spindles are vulnerable to the thermal changes and would depolymerize. Cryopreserved oocytes exhibited serious disturbances of the microtubules immediately after thawing. Fertilization of oocytes with disorganized spindles could lead to chromosomal aneuploidy, digyny, and arrest of cleavage. After incubation, the microtubules would repolymerize in a time-dependent way. Normal fertilization and development of cryopreserved oocytes improved after appropriate incubation and timing of insemination, compatible with recovery of the spindles. With the improvement of survival, fertilization, and cleavage, oocyte cryopreservation would gain an imperative role.     

Clinical applications of induced sputum

The development of standardized methods for sputum induction has improved the quality and reproducibility of sputum samples. This technique has been used to optimize samples in the investigation of pulmonary tuberculosis and lung cancer, but its clinical application as a noninvasive measure of airway inflammation has highlighted the enormous potential of this technique. Sputum induction has allowed researchers to characterize the inflammatory profiles of a variety of airway diseases including asthma, COPD, and chronic cough. To date, the identification of sputum eosinophilia has the greatest clinical value as this predicts a favorable response to corticosteroids and can therefore guide treatment. In asthma and COPD management, protocols aimed at normalizing the sputum eosinophil count have markedly reduced exacerbations without an overall increase in therapy. Currently, no other noninvasive measure of airway inflammation has demonstrated a benefit in reducing exacerbations. The value of sputum induction and analysis is not restricted to the recognition of sputum eosinophilia but also may be used to direct novel antineutrophilic therapies. Thus, it is time for sputum induction to move from the research laboratory to the clinic.     

Clinical applications of bronchoalveolar lavage

The clinical applications of bronchoalveolar lavage are assessed in regard to its current place as an aid for the practicing physician in the management of individual patients.     

Clinical applications of body ventilators

Interest has been increasing in providing ventilatory support in the home for patients with chronic respiratory failure, mainly with the use of positive pressure ventilation via a chronic tracheostomy. However, body ventilators that assist ventilation by applying intermittent negative or positive pressure to the thorax, abdomen, or airway without requiring an artificial airway, can offer distinct advantages for selected patients over systems requiring a permanent airway. These ventilators include the iron lung, portable lung (Portalung), pneumowrap, chest cuirass, pneumobelt, rocking bed, and positive pressure provided via a face or nose mask. They have successfully stabilized or reversed chronic hypercarbia when used intermittently in patients with slowly progressive chronic respiratory failure due to certain neuromuscular diseases and kyphoscoliosis. How they achieve this stabilization has not been clarified, but reversal of chronic respiratory muscle fatigue following periodic rest probably contributes. These ventilators are generally less effective than positive pressure ventilation through a tracheostomy and should be reserved for patients with relatively stable chronic respiratory failure and intact upper airways. However, they have the advantages of simpler operation and less expense, and they allow maintenance of a normal airway.     

Clinical applications of hepatocyte transplantation

The shortage of organ donors is a problem worldwide,with approximately 15% of adult patients with lifethreatening liver diseases dying while on the waiting list. The use of cell transplantation for liver disease is an attempt to correct metabolic defects, or to support liver function as a bridge to liver transplantation and, assuch, has raised a number of expectations. Most of theavailable studies briefly reported here focus on adult hepatocyte transplantation （HT）, and the results are neither reproducible nor comparable, because the meansof infusion, amount of injected cells and clinical variability differ among the studies. To better understand the specific role of HT in the management of end-stage liverdisease, it is important that controlled studies, designedon the principles of evidence-based medicine, be done in order to guarantee the reproducibility of results.     

新型抗栓药的临床应用

<正>抗栓治疗是血栓性疾病(包括动脉和静脉性血栓疾病)的主要防治措施之一。血栓形成的过程包括止血和凝血两大系统的激活和启动,冈此抗栓治疗必须针对这两个系统.应包括抗凝治疗和抗血小板治疗。南于止血过程和凝血过程是同时启动的,且二者相互影响.故抗凝治疗和抗血小板治疗实际上是密不可分的。抗栓治疗目前仍主要依赖于药物治疗。如上所     

Clinical applications of RANK-ligand inhibition

An enhanced rate of bone remodelling fuelled by osteoclastogenesis mediates diseases such as osteoporosis, arthritic bone destruction, Paget's disease and malignancy-induced bone loss. Thus, the control of osteoclastogenesis is of major clinical importance. The receptor activator of nuclear factor κ B (RANK); its ligand, RANKL and decoy receptor, osteoprotegerin, are critical determinants of osteoclastogenesis, and increased RANK signalling is involved in several bone diseases, providing the rationale for RANKL inhibition. The effects of RANKL inhibition are being witnessed in clinical trials of neutralizing fully human monoclonal antibodies that target RANKL (e.g. denosumab) and which induce profound and sustained inhibition of bone resorption. The relative efficacy, cost-effectiveness and side-effects of targeted RANKL inhibition compared with conventional antiresorptive drugs (i.e. bisphosphonates) should be resolved by clinical trials in coming years.     

Copeptin的临床研究进展

Copeptin(和肽素)是精氨酸加压素原羧基末端的一部分,作为精氨酸加压素原的片段,具有生物学效应稳定、检测迅速方便、易保存等特点,且血浆copeptin与精氨酸加压素水平明显相关,可作为其检测的替代物。许多研究表明,copeptin作为一种新型的标志物,与多种疾病的预测、评估及预后有密切关系,该文就近年来对copeptin的临床研究进行综述。