4-S-(5-酰氨基-1,3,4-噻二唑-2-基)-4-脱氧-4′-去甲基表鬼臼毒素衍生物的合成与抗肿瘤活性

基于在4′-去甲基表鬼臼毒素母核C₄位上联结含有杂原子的芳香环取代基,以此考察其结构与活性关系的设想,设计并合成了10个标题化合物。体外L₁₂₁₀白血病细胞与KB细胞生长抑制试验结果表明,这类化合物有较强的抗肿瘤活性。其中化合物SIPI-92-1772,1774,1775,1776,1777与1779的活性超过临床用药依托泊甙。其余化合物活性与依托泊甙相当或略低。     

Estimation of the number of hematopoietic precursor cells during fetal mouse development by covariance analysis

Differentiation of hematopoietic precursor cells results in the formation of clonally related descendent cells. Using the mosaic expression of beta-galactosidase in female mouse fetuses heterozygous for an X-linked lacZ transgene, we analyzed the clonal relationship of the hematopoietic progeny. The proportion of beta-galactosidase positive cells for different T- and B-lymphoid and myeloid cell populations was determined at different stages of fetal development. We found excellent correlations of the proportion of beta-galactosidase expressing cells for all hematopoietic lineages confirming that they share a common ancestry. Therefore, it was possible to estimate the number of common precursor cells (PC) based on binomial distribution and covariance analysis of pairs of different hematopoietic cell populations. Our results obtained from hematopoietic cells at 15.5 to 18.5 days of gestation indicated the presence of 15 to 18 lymphoid and 18 to 22 myeloid/lymphoid specific precursor cells. Statistical analysis of the precursor cell numbers showed a trend of increasing numbers that was highly significant. The precursor cell number was inversely related to maturity of the cell populations analyzed; ie, the lowest number of lymphoid and lymphoid/myeloid precursors was calculated when the most mature CD3+ T-cell population was used for comparison. Determination of PC numbers can therefore be used to assess the relative maturity and developmental potential of individual cell populations.     

MISDIAGNOSES IN A CHINESE NARCOLEPTIC PATIENT WITH DELAYED ONSET OF CATAPLEXY

Narcolepsy is a chronic condition that usually afflicts the patient for decades. It is more common than is generally appreciated. However, it is likely to be misdiagnosed because doctors are unfamiliar with some of the symptoms. Its significant socioeconomic impact on the patient's quality of life warrants prompt medical attention.     

Generalized CNS disease and massive GM1-ganglioside accumulation in mice defective in lysosomal acid beta-galactosidase

Human GM1-gangliosidosis is caused by a genetic deficiency of lysosomal acid beta-galactosidase (beta-gal). The disease manifests itself either as an infantile, juvenile or adult form and is primarily a neurological disorder with progressive brain dysfunction. A mouse model lacking a functional beta-gal gene has been generated by homologous recombination and embryonic stem cell technology. Tissues from affected mice are devoid of beta-gal mRNA and totally deficient in GM1-ganglioside- hydrolyzing capacity. Storage material was already conspicuous in the brain at 3 weeks. By 5 weeks, extensive storage of periodic acid Schiff- positive material was observed in neurons throughout the brain and spinal cord. Consistent with the neuropathology, abnormal accumulation of GM1-ganglioside in the brain progressed from twice to almost five times the normal amount during the period from 3 weeks to 3.5 months. Despite the accumulation of brain GM1-ganglioside at the level equal to or exceeding that seen in gravely ill human patients, these mice show no overt clinical phenotype up to 4-5 months. However, tremor, ataxia and abnormal gait become apparent in older mice. Thus, the beta-gal- deficient mice appear to mimic closely the pathological, biochemical and clinical abnormalities of the human disease.      

What can we learn from the recent blood glucose lowering megatrials?

In the past two decades, we have acquired an enormous amount of knowledge regarding the epidemiology, diagnosis, pathophysiology and treatment of type 2 diabetes and its comorbidities. In addition to the earlier landmark blood lipid and blood pressure lowering trials, the latest blood glucose lowering megatrials represent the zenith of this global effort to prevent and control diabetes, and its devastating consequences. Although many of these latter trials have yielded negative results and have shown the narrow risk‐benefit ratio of intensive treatment in patients with advanced disease, the exceedingly low event rates in these high‐risk patients who were carefully monitored and intensively managed made possible in these clinical trial settings have not been emphasized enough. The heterogeneity of the clinical outcomes in these studies further highlight the complexity of diabetes, which is more than managing a disease, but the multiple needs of a patient with multisystem dysfunction. In the final analysis, what transpires from these megatrials is the need to translate the key components of these studies, namely, protocol, team, documentation and monitoring, into our daily clinical practice to enable the care team to stratify risk, define needs, individualize therapy, monitor progress and reinforce compliance in order to achieve positive outcomes. (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2010.00063.x, 2010)     

Red cell alloantibodies in multiple transfused thalassaemia patients

Background: Thalassaemia major patients require lifelong transfusion support due to which they are prone for a1loimmunization to foreign RBCs. Alloimmunization can he prevented by extended phenotype match blood transfusion. The study was conducted to know the extent of problem of alloimmunization and to find important red cell antibodies in thalassaemia patients.Methods: A cross-sectional study was conducted. A total of 32 thalassaemia patients were enrolled. The specimen was subjected to red cell alloantibody and autoantibody by column gel agglutination technique. R₁^wR₁R₂R₂, rr (papaine and non papain) and 11 cell panel reagent cells were used in screening and identification of alloantibodies respectively.Result: Six (18.8 %) subjects were alloimmunized. All alloimmunized subjects were recipient of more than 20 units of transfusion. Total seven clinically significant alloantibodies were identified. Anti E and anti c were commonest antibodies in four (12.5%) patients.Conclusion: Red cell alloimmunization is an important risk in thalassaemia patient. 71.4% of alloantibodies were anti E and anti c type. Extended phenotype match blood transfusion for Rh-c, and Rh-E antigens or level 2 antigen matching stringency needs to be explored in preventing alloimmunization in thalassaemia patients.