Transposition of DNA inserted into deletions of the Tn5 kanamycin resistance element

Summary Tn5-trp hybrid transposons have been constructed by insertion of a trpPOED Hind III fragment into an in vivo Tn5 internal deletion mutant or by substitution of trp for the internal Tn5 Hind III fragment. These hybrids are called, respectively, Tn409 and Tn410. Both Tn409 and Tn410 will transpose into in the presence of a complementing Tn5 element. In the absence of a wild Tn5, lysogens carrying R1162::Tn409 and R1162::Tn410 plasmids will yield trp phages at less than six per cent of the complemented frequency. This reduction indicates that Tn409 and Tn410 lack a diffusible transposition function provided by wild Tn5 elements. However, the formation of trp phages without complementation is real. Most of these transducing particles contain Tn409 and Tn410 still linked to the carrier R1162 plasmid. This observation suggests that uncomplemented Tn409 and Tn410 elements mediate the formation of -transposon-plasmid cointegrate structures. Thus, the missing transposition function may be involved in resolving these cointegrate structures to the final ::Tn409 or ::Tn410 product.Abbreviations p.f.u. plaque-forming units - MIC minimal inhibitory concentration - LFT low frequency transducing - HFT high frequency transducing     

Organic matter influences phytotoxicity of cadmium to soybeans

Summary Soybeans (Glycine max L. var. Williams) were grown for six weeks in a greenhouse in quartz sand containing 0, 0.5, 1, 2, 4 or 8% (w/w) sterilized peat moss. The cation exchange capacities of the organic matter-sand (OM-S) mixtures ranged from 0.01 to 8.88 meq/100 g dry weight. Imposed on each OM-S mixture was a treatment of 0, 1.25, 2.5, 5.0, 10.0 or 20.0 ppm Cd applied as CdCl₂·21/2H₂O. Height growth was measured weekly and at harvest plants were separated into leaves, stems and roots for dry weight and tissue Cd determinations. For plants grown in sand alone, height growth and dry matter accumulation in all tissues were reduced and Cd content was increased. These effects were correlated with increasing Cd concentration in the rooting medium. Inhibitions in growth by Cd were reduced by addition of organic matter; the amount of alleviation was dependent on both the level of organic matter and the cadmium treatment. In the 0, 0.5 and 1% OM-S mixtures, Cd content in the various tissues was correlated with metal treatment. Tissue levels were markedly reduced for Cd treatments in the 2, 4 and 8% OM-S mixtures, although there was a positive correlation between tissue Cd and the 1.25 and 2.5 Cd treatments. The order of Cd accumulation in the tissues was roots stems>leaves.     

Partial monosomy 7q syndrome due to distal interstitial deletion

Summary A female infant was ascertained at 10 weeks because of failure to thrive and a peculiar cry and was found to have few morphologic variants. Her karyotype was 46,XX,del(7)(q3105: :q3405). The parental karyotypes were normal. At one year she manifested physical retardation and development delay and required surgery for gastroesophageal incompetence. The phenotypic characteristics of this patient and those of six previously reported cases of 7q medial or distal interstitial deletion include many anomalies. Morphologic abnormalities of the head, ears, eyes, mouth, chest, hands, feet, and nerves combined with characteristics of birth weight, growth, and development define a detectable syndrome. An unusual cry may help in the recognition of this new syndrome.     

Cell culture studies on neurofibromatosis (von Recklinghausen)

Summary The growth of strains of fibroblasts derived from patients with neurofibromatosis (NF) was compared with that of strains from appropriate controls in culture medium containing 1% or 15% fetal calf serum. The means of the ratios of final to initial cell numbers do not differ significantly between NF strains and control strains. Weakly significant differences are, however, obtained after conversion of the results to mean numbers of cell population doublings, the NF strains showing the higher numbers. The ratios of final to initial amounts of protein also differ significantly under both sets of growth conditions. High growth parameters occur significantly more frequently among our smaple of 11 NF strains than among our sample of 13 control strains. The possibility of the expression of the NF genotype(s) on the level of the cultured fibroblast-like cells and the possible causes of the large ranges of inter-and intra-individual variations of the results are discussed.     

Regional immunotherapy has a detrimental effect on the response to combined irradiation and chemotherapy in locally advanced non-small cell bronchogenic carcinoma

Summary Twenty-one patients with stage III M₀ non-oat cell bronchogenic carcinoma confined to the thorax were randomized to receive either intrapleural BCG (10⁷ cfu, Tice strain) or intrapleural saline 3 weeks prior to beginning combined irradiation and chemotherapy. Radiation to the primary tumor and regional nodes was given at a dose of 3,000 rad in ten sessions and was followed in 7–14 days by CAMP chemotherapy (cyclophosphamide, adriamycin, methotrexate, and procarbazine) for a planned duration of 6 months. Isoniazid, 300 mg/day, was given to all patients for 3 months starting 1 week after intrapleural therapy. There were no significant differences in pretreatment prognostic factors or in response to radiation therapy. The patients receiving intrapleural BCG in addition to radiation and chemotherapy had a median survival of 18 weeks, significantly shorter than that for the patients receiving intrapleural saline (54 weeks, P=0.017).Presented in part at the 16th Annual Meeting of the American Society of Clinical Oncology, San Diego, California, May 27, 1980     

Cerebral energy metabolism during the onset and recovery from halothane anesthesia

Halothane (1%) was administered to twenty-two gram female Swiss-Albino mice which were sacrificed at times of 15 seconds, 45 seconds, 79 seconds and 5 minutes. Additional animals were exposed for 5 minutes and sacrificed 10 minutes after removal from halothane (recovery). Selected energy metabolites were measured in 100–500 nanogram samples from the inferior colliculus and the ascending reticular activating system.Results from this study showed an increase in glucose levels at 79 seconds, when the animals first lost their righting response. The glucose increase was similar in the inferior colliculus and reticular formation. ATP and phosphocreatine were increased at 45 seconds, and during the sleep period in the ascending reticular activiting system, and returned to normal during the recovery period. In the inferior colliculus, ATP was similarly increased from 45 seconds throughout the time course, whereas phosphocreatine was elevated at 79 seconds, and during recovery only. These data suggest a decrease in utilization of energy metabolities during halothane anesthesia, both in cells of the inferior colliculus and ascending reticular activating system.     

A new genus and two new species of gobiid fishes (Perciformes) from the Chagos Archipelago,Central Indian Ocean

Synopsis A recent (1979) expedition to the Chagos Archipelago resulted in the collection of about 40 new taxa of fishes. A new genus,Trimmatom, and two new species,T. nanus andT. offucius, are described here. The new genus is characterized by having all pelvic-fin rays simple (unbranched), a scaleless body, no head pores, a wide gill opening extending anteroventrally to below the eye, and hypurals 1 and 2 fused to the complex formed by the fusion of the ural centrum and hypurals 3 and 4.T. nanuss andT. offucius are differentiated on the basis of fin ray counts and colour pattern.T. nanus is the smallest vertebrate yet to be described. Mature females with ovaries full of eggs are 8–10 mm in standard length.     

Incorporation of fucose and leucine into PNS myelin proteins in nerves undergoing early Wallerian degeneration

The simultaneous incorporation of [³H]fucose and [1-¹⁴C]leucine into normal rat sciatic nerve was examined using an in vitro incubation model. A linear rate of protein precursor uptake was found in purified myelin protein over 1/2–6 hr of incubation utilizing a supplemented medium containing amino acids. This model was then used to examine myelin protein synthesis in nerves undergoing degeneration at 1–4 days following a crush injury. Data showed a statistically significant decrease in the ratio of fucose to leucine at 2, 3, and 4 days of degeneration, which was the consequence of a significant increase in leucine uptake. These results, plus substantial protein recovery in axotomized nerves, are indicative of active synthesis of proteins that purify with myelin during early Wallerian degeneration.     

The stylet apparatus of the nemertean Paranemertes Peregrina: Its ultrastructure and role in prey capture

Summary The nemertean Paranemertes peregrina captures prey by using an eversible proboscis that is armed with a stylet apparatus. The apparatus consists of several reserve stylet sacs and a central stylet that is attached to a granular mass, called the basis. When the proboscis is everted, the central stylet is used to stab prey such as nereid polychaetes, and paralytic neurotoxins, produced in the proboscis, are inserted in the stylet-induced wounds. The central stylet averages 85 m in length and has helically-arranged grooves along its shaft. The proximal piece of the central stylet is anchored to the basis, apparently by adhesive granules in the anterior end of the basis. A basis sheath surrounds the basis and is continuous posteriorly with a duct, called the ductus ejaculatorius. Secretions in the ductus ejaculatorius may contain some of the toxin that is used to immobilize the prey. The contents of the duct are probably injected into the prey by way of the grooves on the central stylet. In the region anterior to the central stylet, there are numerous glandular cells and anchor cells that are believed to attach the stylet apparatus to the prey during attack. Each reserve stylet sac is lined by a simple epithelium. One of the epithelial cells, called the styletocyte, is greatly enlarged and fills the lumen of the sac. Several reserve stylets are assembled in a styletocyte. Each reserve stylet is formed within a membrane-bound vacuole associated with the Golgi apparatus and is composed of an inner organic core surrounded by an inorganic cortex. A duct connects each reserve stylet sac with the area around the central stylet and provides a pathway for the transfer of reserve stylets during replacement of the central stylet.     

Fine structure of ocelli in larvae of an archiannelid,Polygordius cf. appendiculatus

Summary The ocelli of trochophore and segmented larvae of the archiannelid Polygordius cf. appendiculatus were studied by electron microscopy. An eye consists of two pigmented supportive cells forming an eyecup that encloses one sensory cell bearing one (trochophore) or two (segmented larva) ranks of microvilli and one adventitious cilium. Remarkably abundant tubules (submicrovillar endoplasmic reticulum) radiate from the perinuclear region of the sensory cell, which lies outside the ocellus, toward its receptoral end. Possible functions of the tubules are proposed: carriers of ions, metabolites and photopigments; pinocytic uptake of products resulting from photoreception; storage of membrane; and light guides. Finally, the eyes of Polygordius larvae are believed to have evolutionary significance and provide further support for Eakin's theory of diphyletic origin of photoreceptors.