重金属离子对骨骼肌肌动球蛋白的超沉淀作用

从家兔骨骼肌中提取肌动球蛋白,并对重金属离子对其超沉淀的影响进行了研究。低浓度的Cd~(2+)和Pb~(2+)表现出与Cd~(2+)类似的激活作用,主要是加快超沉淀的速度,Hg~(2+)的激活作用较小。离子浓度大于100μmol/L,Cd~(2+)和Pb~(2+)开始表现抑制作用,即抑制超沉淀的速度和幅度。Hg~(2+)的抑制效应最为强烈,浓度大于10μmol/L即开始出现抑制,大于20μmol/L便可阻止超沉淀的发生。重金属离子作用于肌钙蛋白调节体系,为金属中毒机制提供了新的佐证。     

Nonuniform myosin expression along single fibers of chronically stimulated and contralateral rabbit tibialis anterior muscles

Using a combined histochemical and biochemical technique, single fiber analyses were performed on chronically stimulated and contralateral tibialis anterior (TA) muscles of the rabbit. The major fiber population (60%) in 30 days stimulated TA was transforming fibers (type IIC). Some of these fibers displayed a nonuniform distribution of histochemically assessed myofibrillar actomyosin ATPase (mATPase) activity. This heterogeneity of mATPase activity along the fibers was verified in longitudinal sections and by microphotometric evaluation of mATPase staining intensities in serial cross-sections. Biochemical analyses of single fiber segments revealed that these C fibers not only coexpressed fast- and slow-myosin subunits but did so nonuniformly along their length. The distribution of fast- and slow-myosin subunits in these fibers was not random but focal. Variations in myosin expression were also observed in some of the C fibers in the contralateral TA. As opposed to the transforming fibers in the stimulated TA, heterogeneities of mATPase activity and myosin subunits in these contralateral C fibers were less focal and more gradual. These findings suggest that muscle fibers in chronically stimulated TA and the contralateral muscle do not transform synchronously or uniformly along their length.     

The induction of stress proteins (hsp) in Oniscus asellus (Isopoda) as a molecular marker of multiple heavy metal exposure: I. Principles and toxicological assessment

The induction of stress-70 (hsp70) and stress-60 (hsp60, chaperonin 60) in the terrestrial woodlouse, Oniscus asellus, after exposure to various heavy metals and heavy metal combinations was investigated by means of standard Western-blot using monoclonal antibodies. The expression of stress-70 was found to react much more sensitively to metal contamination than that of stress-60. The general course of the stress-70 response to increasing metal concentration was found to be similar for all treatments. Based on the obtained results, this course could be divided into three zones: in the first zone, the expression of stress-70 proteins was only marginally increased by comparatively low metal concentrations; in the second zone, strong induction of stress-70 occurred and the ability of the heat shock system to react to increased metal concentrations reached its climax; and in the third, non-compensation zone, a further increase in heavy metal concentration resulted in a decline of stress-70 levels, which can be interpreted as a result of pathological tissue damage. Combinations of metals were found to increase the stress- 70 level more intensely than related concentrations of singularly applied metals. Based on these studies, a ranking scheme of increasing toxicological impact of a variety of heavy metal combinations was composed     

卡托普利治疗162例重度高血压疗效观察

目的：对162例重度高血压病人进行系统。方法：治疗组和对照组在诊断标准，同时治疗、服药观察压效果，结果：通过对照比较，联合用药降压效果明显，总有效率为94．19％，结论：重度高压病人在明确诊断以后，及时联合服药及辅助治疗，达到明显降低效果，提高了对高血压病的治疗水平。     

Characteristic Levels of Some Heavy Metals from Brazilian Canned Sardines (Sardinella brasiliensis)

The total concentration of metals Cu, Fe, Mn, Zn, Sn, Cd, Cr and Pb were determined in different brands of sardines canned in soybean oil and tomato sauce, commercialized in Brazil. The sample was dissolved after wet digestion with acids and the measurements were done by flame atomic absorption spectrometer (AAS). The metals that presented higher concentrations were Fe and Zn ranging from 20.96 to 88.83 and 16.16 to 36.09 μg/g, respectively. The highest values were found in sardines canned in tomato sauce. Cu, Mn and Sn ranged from 1.31 to 2.25; 1.53 to 17.55 and 2.07 to 4.57 μg/g, respectively. When compared to those metals, the Cd, Cr and Pb contents in (μg/g) presented lower values, ranging from 0.19 to 0.38, 0.46 to 1.18 and 0.77 to 2.15, respectively. The contents of Cd and Pb did not present values above the maximum limit permissible by Brazilian legislation, that are, respectively, 1.0 and 2.0 μg/g. On the other hand, the Cr concentrations were above the limit value of 0.10 μg/g. The concentrations of Pb (2.15 μg/g) observed in brand P were above the permissible limit. In general, only brand P presented the highest levels of metals. This can be attributed to differences in the process of canning and sardines quality.     

A case of chronic renal allograft failure by effects of elderly donor

Abstract: We experienced a case of chronic renal allograft failure from an elderly donor. A 23-year-old man received living-related transplantation in 1998 . The donor was his father, 66 years old and 69 kg body weight. The recipient was 88 kg and the cause of the renal failure was IgA nephropathy. The graft function decreased 2 months after transplantation. One year later, proteinuria and haematuria developed. Six months later, when the creatinine rose to 2.5 mg/dL, a renal transplant biopsy was performed. Characteristic microscopic features were: diffuse segmental to global glomerulosclerosis, hypertrophy of non-sclerotic glomerulus, tubular atrophy, arteriolar hyalinosis, interstitial lymphocytic infiltration with tubulitis and anti-IgA deposition on glomeruli. The pathological diagnoses were recurrent IgA nephropathy, acute rejection and chronic cyclosporin nephrotoxicity. Diffuse glomerulosclerosis as well as glomerular hypertrophy might be the end result of hyperfiltration, which was a consequence of a small number of functioning nephrons. The old age of the donor and the heavy body weight of the recipient could be risk factors for this case.     

Multiple Myeloma: New Evidence and Insights from the Immunoglobulin Heavy Chain Gene and Phenotypes

DNA analysis of the Ig genes has been utilized to delineate the stages of differentiation of normal and malignant B-lineage cells, since the mechanisms involved in V(D)J recombination, somatic hyper-mutations, and class switch are developmentally regulated. Somatic mutations which result in amino acid substitutions are observed frequently in the Ig variable region genes in multiple myeloma (MM), but there is no intraclonal variation. This fact suggests that the target cell of malignant transformation in MM is a B-lineage cell which already has undergone antigenic selection. This B-lineage cell probably corresponds to a pre-plasma cell or a plasma cell rather than a memory B cell. Tumour cells which share an identical third-complementarity-determining-region (CDR3) sequence with the myeloma cells can be detected from the various fractions representing different stages of B-cell differentiation, such as CD34+, CD20+CD10+, CD20+CD21+, CD20+CD19- cells from the peripheral blood. Thus, the tumour cells in MM are composed of immunophenotypically heterogeneous subpopulations at various stages of differentiation, similar to normal B-lineage cells. These results imply that there is an analogous developmental pathway between the normal B-lineage cells and the tumour cells of MM. Dedifferentiation to the stem cell level may be essential to the malignant transformation in MM.     

兔下颌角截骨后咬肌适应性变化

目的通过对兔下颌角弧形截骨后咬肌相关指标测定，研究咬肌在骨架缩短后的变化规律。方法3个月龄雌性新西兰大白兔25只，行左侧下颌角弧形截骨，右侧不手术作为自身对照。2、4、8、12和24周分别处死5只动物，双侧咬肌总量称重。取双侧下颌角中点浅部咬肌，行HE、ATP酶染色。结果左侧咬肌重量减轻与右侧差异显著，肌小节长度2周和4周术侧缩短，8周后恢复正常；部分肌纤维Ⅰ型向Ⅱ型转化；Ⅰ、Ⅱ型肌纤维面积左侧较右侧减小。结论兔下颌角截骨术后肌小节长度、肌纤维转型、咬肌细胞面积发生相应变化，表明下颌骨架缩短后咬肌发生适应性的改建。     

Immunoglobulin Gene Analysis of Cutaneous Pseudolymphoma by Polymerase Chain Reaction

Polymerase chain reaction (PCR) was used to amplify the V-D-J region of the immunoglobulin heavy chain gene from DNA extracted from the formalin fixed, paraffin embedded skin of 3 cases of pseudolymphoma. The products were electrophoresed and observed under ultraviolet light after ethidium bromide staining. Specimens of two cases showed smears of polyclonal amplified DNA. The specimen of one case (Case 3), however, showed a single band with a smear. The presence of monoclonality in B lymphocyte populations may suggest the possibility of low grade malignancy of pseudolymphoma or transformation to malignant lymphoma in the future.