双波长紫外分光光度法测定贝母中腺苷和胸苷的含量

将4种贝母的甲醇提取物经薄层色谱法粗分离后,直接用双波长紫外分光光度法测定其含量。结果表明,该方法线性关系好,腺苷和胸苷标准曲线的相关系数均为0.9999,同时也发现平贝、炉贝和伊贝中腺苷都占核苷总量60%以上,而浙贝中仅占约40%,提示贝母生药的抗凝血活性可能与贝母中核苷类化合物的种类和含量的差别有关。     

Paraganglioma of the cauda equina with associated intramedullary cyst: MR findings.

The MR imaging features of a paraganglioma of the cauda equina with associated spinal cord cysts are presented. MR imaging showed the tumor to be isointense with the spinal cord on all pulse sequences and to enhance homogeneously. The intramedullary cysts had increased signal intensity on proton density- and T2-weighted images, and involved the cervical and thoracic regions.     

Angioedema due to angiotensin-converting enzyme inhibitor use: Radiographic findings in 3 patients

Angioedema of the oropharynx and hypopharynx due to oral angiotensin-converting enzyme (ACE) inhibitors is a potentially life-threatening event and has not been well described in the radiology literature. A retrospective review of the clinical and radiologic findings in three patients with angioedema due to ACE inhibitor use was performed.Our subgroup of patients treated with ACE inhibitors presented with varying degrees of dysphagia, dyspnea, and facial swelling. Plain radiographic findings included enlargement of the epiglottis, aryepiglottic folds, and prevertebral and submental soft tissue. Computed tomography confirmed extensive retropharyngeal and subcutaneous edema. Clinical symptoms resolved in each case in 24–48 hours with cessation of the ACE inhibitor and concomitant steriod therapy.Our cases demonstrate the typical clinical and radiographic presentation of neck angioedema in the setting of ACE inhibitor use. As ACE inhibitors are increasingly being used as first-line agents in the treatment of hypertension, we caution that neck angioedema may be encountered with increased frequency in adults. Early recognition and immediate intervention result in rapid resolution of this potentially life-threatening event.     

Calcium ionophore-induced acrosome reaction correlates with fertilization rates in vitro in patients with teratozoospermic semen

The aim of this study was to determine the relationship between calcium ionophore A23187-induced acrosome reaction (AR) and sperm fertilizing ability. Semen samples remaining after preparation for standard IVF were studied in 109 patients who had sperm concentrations > or =20 x 10(6)/ml. Ionophore-induced AR was performed on motile spermatozoa selected by centrifugation on a Percoll gradient. Semen analysis was performed using standard methods. Patients with higher (>50%, n = 76) fertilization rates had significantly higher ionophore-induced AR than patients with lower (<50%, n = 33) fertilization rates (49 +/- 14 versus 38 +/- 21%, P < 0.05). When the data from all patients were analysed by logistic regression, only the percentage sperm motility in insemination medium and ionophore-induced AR were significantly related to fertilization rates. Similar results were also obtained when the data from a subgroup of patients with poor (<15% normal) sperm morphology were analysed. However, when patients with normal sperm morphology > or =15% were analysed separately, only sperm count and the percentage of spermatozoa with progressive motility in semen were significantly related to fertilization rates. In conclusion, ionophore- induced AR was significantly related to fertilization rates in vitro mainly in patients with teratozoospermic semen. Tests for ionophore- induced AR may provide additional information about sperm fertilizing ability but may not indicate specific defects of the physiological AR.      

Functional MRI of visuospatial working memory in schizotypal personality disorder: a region-of-interest analysis

BACKGROUND: Functional MRI studies have begun to identify neural networks implicated in visuo-spatial working memory in healthy volunteers and patients with schizophrenia. The study of schizotypal personality disorder (SPD) provides regional analysis in unmedicated patients in the schizophrenia spectrum. METHOD: Unmedicated patients with SPD by DSM-IV criteria and normal controls were assessed with fMRI while performing a visuo-spatial working-memory task. It required the subjects to retain the location of three dots located on the circumference of an imaginary circle and then respond to a query display in which one dot was presented and the subject required to press a button to indicate whether the probe dot location was previously displayed. Subject groups did not differ significantly in spatial memory scores. The exact Talairach and Tournoux coordinates of brain areas previously reported to show activation with spatial memory tasks were assessed. RESULTS: The majority of these locations showed BOLD response activation significantly less in patients during the memory retention period, including the left ventral prefrontal cortex, superior frontal gyrus, intraparietal cortex and posterior inferior gyrus. Regions in the right middle prefrontal and prestriate cortex showed greater activation at a trend level for patients with SPD than for normal controls. In addition, we replicated the findings of increased activation with the task in healthy volunteers in the premotor areas, ventral prefrontal cortex and parietal cortex. CONCLUSIONS: SPD patients show decreased activation compared to healthy volunteers in key frontal regions and we also provided a partial replication of findings reported in healthy subjects.     

Detection of reactive oxygen species (ROS) and apoptosis in human fragmented embryos

In human in-vitro fertilization (IVF)-embryo transfer, the in-vitro culture environment differs from in-vivo conditions in that the oxygen concentration is higher, and in such conditions the mouse embryos show a higher concentration of reactive oxygen species (ROS) in simple culture media. ROS are believed to cause damage to cell membranes and DNA fragmentation in somatic cells. This study was conducted to ascertain the level of H2O2 concentration within embryos and the morphological features of cell damage induced by H2O2. A total of 62 human oocytes and embryos (31 fragmented, 15 non-fragmented embryos, 16 unfertilized oocytes) was obtained from the IVF-embryo transfer programme. The relative intensity of H2O2 concentrations within embryos was measured using 2',7'-dichlorodihydrofluorescein diacetate by Quanti cell 500 fluorescence imaging and DNA fragmentation was observed with transmission electron microscopy and an in-situ apoptosis detection kit. The H2O2 concentrations were significantly higher in fragmented embryos (72.21 +/- 9.62, mean +/- SEM) compared to non-fragmented embryos (31.30 +/- 3.50, P < 0.05) and unfertilized oocytes (30.75 +/- 2.67, P < 0.05). Apoptosis was observed only in fragmented embryos, and was absent in non-fragmented embryos. Electron microscopic findings confirmed apoptotic bodies and cytoplasmic condensation in the fragmented blastomeres. We conclude that there is a direct relationship between increased H2O2 concentration and apoptosis, and that further studies should be undertaken to confirm these findings.      

Interchromosomal duplications of the adrenoleukodystrophy locus: a phenomenon of pericentromeric plasticity

A 9.7 kb segment encompassing exons 7-10 of the adrenoleukodystrophy (ALD) locus of the X chromosome has duplicated to specific locations near the pericentromeric regions of human chromosomes 2p11,10p11, 16p11 and 22q11. Comparative sequence analysis reveals 92-96% nucleotide identity, indicating that the autosomal ALD paralogs arose relatively recently during the course of higher primate evolution (5-10 million years ago). Analysis of sequences flanking the duplication region identifies the presence of an unusual GCTTTTTGC repeat which may be a sequence-specific integration site for the process of pericentromeric- directed transposition. The breakpoint sequence and phylogenetic analysis predict a two-step transposition model, in which a duplication from Xq28 to pericentromeric 2p11 occurred once, followed by a rapid distribution of a larger duplicon cassette among the pericentromeric regions. In addition to facilitating more effective mutation detection among ALD patients, these findings provide further insight into the molecular basis underlying a pericentromeric-directed mechanism for non- homologous interchromosomal exchange.      

Artificial insemination and in-vitro fertilization using donor spermatozoa: a report on 15 years of experience

Donor insemination (DI) using cryopreserved semen commenced at The Royal Women's Hospital in 1976. Over the next 15 years we performed 5953 treatment cycles to achieve 816 pregnancies (13.7% per cycle) and 706 live births. In-vitro fertilization (IVF) using donor spermatozoa commenced in 1986. Over the next 5 years we performed 303 treatment cycles for 185 couples. Including subsequent transfer of cryopreserved embryos, a total of 33% of couples achieved a successful pregnancy by IVF. Statistical analysis indicated that, for DI pregnancies, the most important semen variable was the percentage post-thaw motility, whilst for normal fertilization in IVF it was the pre-freeze motility. These results may be explained by the compensatory effects of post-thaw processing of spermatozoa for IVF, but not for DI in our clinic.