Molecular characterization of a patient with del(1)(q23–q25)

Summary We report a patient (S.T.) with multiple congenital anomalies and developmental delay associated with an interstitial deletion of 1q23–1q25. Molecular analysis of the deletion was performed using DNA markers that map to 1q. Five DNA markers, MLAJ-1 (D1S61), CRI-L1054 (D1S42), HBI40 (D1S66), OS-6 (D1S75), and BH516 (D1S110), were demonstrated to be deleted. Informative polymorphisms demonstrated this to be a de novo deletion of the maternally derived chromosome. Deletion status was determined using restriction fragment length polymorphism (RFLP) analysis supplemented with densitometry in the experiments where RFLP analysis was not fully informative. Deletions were confirmed by Southern analysis using genomic DNA from a somatic cell hybrid retaining the del(1)(q23–q25) chromosome that was constructed from patient S.T. Flow karyotyping confirmed the deletion and estimated that the deletion encompassed 11,000–16,000 kb. The clinical and cytogenetic characteristics of S.T. are compared with those of ten previously described patients with monosomy 1q21–1q25.     

Developmental Pattern for Phosphatidylserine Decarboxylase in Rat Brain

In adult rats, a significant portion of brain ethanolamine glycerophospholipids are synthesized by a pathway involving phosphatidylserine decarboxylase, a mitochondrial enzyme. We have now examined whether this enzyme plays a particularly prominent role during development. Activities for both phosphatidylserine decarboxylase and succinate dehydrogenase (another mitochondrial enzyme) were determined in brain homogenates from rats 5 days of age to adulthood. Succinate dehydrogenase activity, expressed on a per unit brain protein basis, increased markedly during development. This pattern has been reported previously and is as expected from the postnatal increase in oxidative metabolism. In contrast, phosphatidylserine decarboxylase activity decreased 40% from 5 to 30 days of age. The apparent Km for brain phosphatidylserine decarboxylase was 85 microM in both young (8- and 20-day-old) and adult animals. Parallel studies in vivo were carried out to determine the contribution of the phosphatidylserine decarboxylase pathway, relative to pathways utilizing ethanolamine directly, to the synthesis of brain ethanolamine glycerophospholipids. Animals were injected intracranially with a mixture of L-[G-3H]serine and [2-14C]ethanolamine and incorporation into the base moieties of the phospholipids determined. The 3H/14C ratio of ethanolamine glycerophospholipids decreased about 50% during development. Our studies in vitro and in vivo both suggest that phosphatidylserine decarboxylase plays a significant role in the synthesis of brain ethanolamine glycerophospholipids at all ages, although it is relatively more prominent early in development.     

水分胁迫下露花光合型的转变

CAM植物按其对环境的反应可分为两种类型:即专一CAM植物和兼性CAM植物。前者不易受外界环境的变化而改变其CAM性质;后者的光合型可随季节和水分胁迫等而发生变化,也可因人工诱导作用而使其由C_3型转变为CAM型。     

Differentiation properties of pure populations of human dystrophic muscle cells

The interpretation of the majority of studies of Duchenne muscular dystrophy (DMD) has been complicated by the heterogeneous composition of the cultures used. In addition to muscle cells, muscle tissue contains adipocytes and fibroblasts and the proportion of these cell types varies, especially in disease states. To overcome this problem we developed culture conditions which permitted isolation and characterization of pure populations of clonally derived human muscle cells [1, 2]. Here we report the successful application of these methods to muscle cells from biopsies of individuals with diagnosed DMD. The normal and mutant human muscle cells were used in experiments of muscle differentiation in the same manner as cell lines. Frozen-stored cells were thawed, plated in a series of replicate plates, and allowed to differentiate under similar culture conditions. Yet, in contrast with cell lines, the cells were karyotypically normal, not altered by adaptation to long-term culture, and had a finite lifespan. We have systematically analysed specific properties of the normal and DMD muscle cells which differentiated in culture. The kinetics and extent of myoblast fusion, myotube morphology, and the accumulation and distribution of membrane acetylcholine receptors were monitored. In addition, the isozyme composition of creatine kinase and its intracellular and extracellular distribution were determined. Our results indicate that DMD muscle cells are fully capable of initiating myogenesis in culture and do not differ from normal muscle in several important parameters of differentiation.     

Role of basidiospores as inocula of mycorrhizal fungi of birch

Summary Fruitbodies of sheathing mycorrhizal fungi collected under birch (Betula pendula andB. pubescens) were suspended over pots of soil and the resulting spore-supplemented soils were planted with sedlings ofB. pendula. Inocybe lacera, I. lanuginella, Hebeloma sacchariolens andH. leucosarx formed mycorrhizas readily.Lactarius pubescens andLeccinum roseofracta did not form mycorrhizas from basidiospore inocula, even after prolonged periods of seedling growth.Paxillus involutus gave equivocal results, perhaps because the soil was unsuitable for this species. Storage of the basidiospore-supplemented soils for 6 months in outdoor conditions or in a growth room at 18°C did not materially alter the results.The results are discussed in relation to the concept of mycorrhizal succession.     

Freeze-drying characteristics ofSaccharomyces cerevisiae andSaccharomyces carlsbergensis

The dispersal of yeast clumps to the unicellular state by certain sugars, does not increase the percentage survival after freeze-drying. Neither are those changes in cell-wall composition which occur upon ageing of the cell, and which are detectable by means of snail-gut enzymes, related to this cellular property. However, pre-treatment, with -mercaptoethanol, of a strain ofSaccharomyces carisbergensis increased the survival rate. This may be due to the reduction of certain sites in the cell wall. The oxygen consumption of yeast cultures before and after freeze-drying, agree with the hypothesis that low viabilities can arise from localized cellular damage which prevents cell reproduction by budding.     

Modified Agglutination Test for Pasteurella tularensis

Several modifications in technique were incorporated into the standard agglutination test for Pasteurella tularensis. Reciprocal shaking of all tubes in a Kahn shaker was introduced to increase the rate of agglutination and quantity of agglutinated cell mass, making it possible to report preliminary results within 4 hr. Increased incubation time at a higher temperature was used to favor the rate of agglutination. A serum control for each serum tested was necessary to detect false positive tests. Finally, a verification procedure with 5% NaCl used as the diluent was instituted to prevent these false positive reactions.     

A method for the estimation of 6-oxygenated metabolites of progesterone in urine

1. A method is described for the estimation of the 6-oxygenated metabolites of progesterone in urine. After hydrolysis the extract of urine is chromatographed on alumina to obtain a fraction containing mainly the 6-oxygenated metabolites. This fraction is oxidized to convert the metabolites into pregnane-3,6,20-triones, which are estimated as the dinitrophenylhydrazones. 2. The reliability criteria of the method are presented. Normal subjects excrete 0.1-0.6mg./day, and at the end of pregnancy values of 3.3-11.6mg./day are obtained.