Complete restoration of a wild-type mtDNA genotype in regenerating muscle fibres in a patient with a tRNA point mutation and mitochondrial encephalomyopathy

Replicative segregation of mitochondrial DNA (mtDNA) can produce large differences in the proportions of wild-type and mutant mtDNAs in different cell types of patients with mitochondrial encephalomyopathy. This is particularly striking in the skeletal muscle of patients with Kearns-Sayre syndrome (KSS), a sporadic disease associated with large- scale mtDNA deletions, and in sporadic patients with tRNA point mutations. Although the skeletal muscle fibres of these patients invariably contain a large proportion of mutant mtDNAs, mutant mtDNAs are rare or undetectable in satellite cells cultured from the same muscle biopsy specimens. Since satellite cells are responsible for muscle fibre regeneration, restoration of the wild-type mtDNA genotype might be achieved in these patients by encouraging muscle regeneration. To test this concept, we re-biopsied a patient with a KSS phenotype and a mtDNA point mutation in the tRNAleu(CUN)gene and analysed muscle fibres regenerating at the site of the original muscle biopsy. Regenerating fibres were identified by morphological criteria and by expression of neural cell adhesion molecule (NCAM). All such fibers were positive for cytochrome c oxidase (COX) activity by cytochemistry and essentially homoplasmic for wild-type mtDNA, while the majority of non-regenerating fibres were COX-negative and contained predominantly mutant mtDNAs. These results demonstrate that it may be possible to improve muscle function in similar patients by methods that promote satellite cell incorporation into existing myofibres.      

First trimester development of human chorionic villous vascularization studied with CD34 immunohistochemistry

Normal chorionic villous vascularization is essential for the undisturbed development of pregnancy. Defective vasculogenesis may play a role in pathological pregnancy. To assess pathological chorionic villous vascularization, normal vascularization has to be defined first. Few data are available on this topic. The aim of this study was therefore to investigate normal chorionic villous vascularization in ultrasound-dated first trimester pregnancies from week 5 menstrual age to week 12 (n = 41), using quantitative CD34 immunohistochemistry. Two important processes in chorionic villous vascularization were quantitatively illustrated: (i) maturation, reflected by an increase of the total number of luminized vessels as opposed to non-luminized haemangioblastic cords and (ii) margination, due to a decrease of villous stromal area and an increase of total villous vascular area. The percentage of villous stromal area occupied by vascular elements (area difference %) increased from 0.7% in week 5-2.5% in week 10. Therefore, the area of the villous stroma occupied by vascular elements increases and the vessels are situated closer to the trophoblastic layer suitable for fetal-maternal exchange. There was also a trend in increased number of peripheral vessels (2.0 in week 5 to 4.6 in week 10), supporting both developmental mechanisms. In conclusion, in exactly dated normal human first trimester pregnancies, development of the chorionic villous vascular system seems to be mostly characterized by maturation of luminized vessels from primitive haemangioblastic cords, and margination to a situation of peripherally located vessels.      

Retrograde tubal embryo transfer in natural cycle in-vitro fertilization

Two modes of embryo transfer, uterine and tubal, were compared following natural cycle in-vitro fertilization (IVF). Only patients with patent Fallopian tubes were included in the study. Tubal embryo transfer was performed by retrograde tubal cannulation without analgesia on an outpatient basis. Tubal transfer conferred no benefit compared with uterine transfer in male factor infertility with positive fertilization (pregnancy rates of 15.8% in both groups). Although tubal embryo transfer in the patients with unexplained infertility improved the pregnancy rates from 7.8% in uterine transfer (5/64) to 17.6% in the tubal transfer group (13/74), this improvement was not statistically significant.      

European cervical cancer screening：experiences and results

1　ＯｖｅｒｖｉｅｗｏｆｆｅｍａｌｅｍａｌｉｇｎａｎｃｉｅｓｉｎＥｕｒｏｐｅＣａｎｃｅｒｉｎｃｉｄｅｎｃｅａｎｄｍｏｒｔａｌｉｔｙｅｓｔｉｍａｔｅｓｆｏｒ 1995ｗｅｒｅｒｅｐｏｒｔｅｄｒｅｃｅｎｔｌｙｆｏｒ 38ｃｏｕｎｔｒｉｅｓｉｎＥｕｒｏｐｅ[1] .Ｔｈｅｒｅｗｅｒｅｅｓｔｉｍａｔｅｄ 2 .6ｍｉｌｌｉｏｎｎｅｗｃａｓｅｓｏｆｃａｎｃｅｒｉｎＥｕｒｏｐｅｉｎ 1995 ,ｒｅｐｒｅｓｅｎｔｉｎｇｏｖｅｒｏｎｅ ｑｕａｒｔｅｒｏｆｔｈｅｗｏｒｌｄｂｕｒｄｅｎｏｆｃａｎｃｅｒｗｈｉｌｅＥｕｒｏｐｅ’ｓｉｎｈａｂｉ…     

Relative contributions of human types 1 and 2 T-helper cell-derived eosinophilotrophic cytokines to development of eosinophilia

The relative contributions of type 1 and 2 T-helper (Th1 and Th2) cell- derived interleukin (IL-5), granulocyte-macrophage colony-stimulating factor (GM-CSF), and IL-3 were studied in the regulation of sequential events in the development of eosinophilia. Using eosinophils from normal donors and neutralizing antibodies that selectively block cytokine activities, we analyzed the effects of these cytokines in supernatants (SN) of well-characterized allergen-specific Th2 and Th1 T- lymphocyte clones (TLC) generated from atopic and nonatopic individuals, respectively. Eosinophil colony formation from CD34+ bone marrow progenitor cells in semisolid cultures could be induced both by Th1 and Th2 SN, mainly mediated by the synergistic effects of GM-CSF and IL-3, whereas IL-5 had only a minor additive effect. High production of mature eosinophils in liquid cultures of unseparated mononuclear bone marrow cells could only be induced by Th2 SN, which could be more than 90% blocked by anti-IL-5, but not by anti-IL-3 or anti-GM-CSF. Chemotaxis of mature peripheral blood eosinophils could equally well be induced by Th1 and Th2 SN, although the relative contribution of the individual cytokines was clearly different in the two sets of SN. Priming of platelet-activating factor (PAF) release by peripheral blood eosinophils was regulated by additive effects of the three cytokines and was stronger induced by the Th2 SN than by the Th1 SN. The present results indicate that IL-5, GM-CSF, and IL-3 control eosinophils throughout the course of development of eosinophilia, having different individual contributions in different compartments. The apparent strong and selective IL-5-dependence of certain yet undefined steps in eosinophil production in the bone marrow supports the concept of the generally assumed causal relation between predominant activation of IL-5-producing Th2 cells in response to allergens and development of eosinophilia in atopic disease.     

Simulated pulmonary nodules: detection with dual-energy digital versus conventional radiography

Performance of a prototype dual-energy digital chest radiography unit in detecting calcified and noncalcified simulated pulmonary nodules was compared with that of a highly optimized, conventional system. Nodules ranging in size (0.5, 1.0, and 1.6 cm), in number (five to 11), and in calcium content (0-25 mg) were superimposed over the lungs of a frozen, unembalmed, human chest phantom. For each technique, six observers examined 50 posteroanterior projections with different randomized nodule locations. Detection consisted of locating and assigning a level of confidence to each perceived nodular opacity. The resulting plots of the true-positive fraction versus the mean number of false-positive calls per projection indicate that for both calcified and noncalcified nodules, the digital unit performed significantly better (P less than .01).