The 5' terminus of the RNA moiety of U1 small nuclear ribonucleoprotein particles is required for the splicing of messenger RNA precursors

We have investigated the role of small nuclear ribonucleoprotein particles (snRNPs) in the in vitro splicing of messenger RNA precursors by a variety of procedures. Removal of the U-type snRNPs from the nuclear extracts of HeLa cells with protein A-Sepharose-coupled human autoimmune antibodies leads to complete loss of splicing activity. The inhibition of splicing can be prevented by saturating the coupled antibodies with purified nucleoplasmic U snRNPs prior to incubation with nuclear extract. We further demonstrate that an intact 5' terminus of U1 snRNA is required for the functioning of U1 snRNP in the splicing reaction. Antibodies directed against the trimethylated cap structure of the U snRNAs inhibit splicing. Upon removal of the first eight nucleotides of the U1 snRNA in the particles by site-directed hydrolysis with ribonuclease H in the presence of a synthetic complementary oligodeoxynucleotide splicing is completely abolished. These results are in strong support of current models suggesting that a base-pairing interaction between the 5' terminus of the U1 snRNA and the 5' splice site of a mRNA precursor is a prerequisite for proper splicing.

[Value of sonography, computed tomography and angiography in adrenal diagnosis]

Between 1979 and 1982, 47 patients with pathological process of the adrenals were surgically treated after preceding thorough non-evasive angiographic diagnosis (6 phaeochromocytomas, 20 adrenal adenomas, 8 adrenal hyperplasias, 5 adrenal carcinomas, 5 adrenal cysts and 3 adrenal metastases). The most consistently accurate results were obtained via adrenal phlebography with an accuracy of 94%. This was followed by non-evasive computed tomography (87%). Compared with the data given in literature, hormone determination in the adrenal venous blood was less favourable (79%). Selective adrenal arteriography, which was used less often, yielded correct results in 83% of the cases, whereas the number of accurate diagnoses achieved via sonography was lowest with 54%.

Splicing of in vitro synthesized messenger RNA precursors in HeLa cell extracts

Using a whole cell extract of HeLa cells, we synthesized unspliced RNAs containing the first two leaders and the first intervening sequence of the adenovirus 2 major late transcription unit. Upon incubation of these pre-mRNAs in reaction mixtures containing a nuclear extract and a postnuclear fraction (S100), removal of the first intervening sequence and concomitant joining of the first leader to the second leader was observed. This splicing reaction requires proteins, Mg2+ ions, and ATP. The S100 fraction alone has no splicing activity but stimulates splicing when added to the nuclear extract. Upon fractionation of the postnuclear S100 by chromatography on ion exchange and gel filtration columns, the stimulatory activity copurifies with small ribonucleoprotein particles.

[Frequency of kidney cyst wall cancer--results of 22,000 ultrasound studies]

In 22 198 sonographic examinations of the epigastric region, the authors identified 759 renal cysts (3.4%) and 165 renal tumours (0.74%). The percentage of incidence of the renal cysts is identical with that found in post-mortem examinations, whereas tumours were distinctly more frequent. Tumours of the cystic wall had been found in 0.5% of all sonographically diagnosed cysts and in 4% of renal cysts examined via fine-needle biopsy. Of the latter cysts (i.e. out of the 4% of cysts diagnosed by fine-needle biopsy), which were associated with tumours, two had been diagnosed as tumour suspects via sonography. Hence, the sonographic absence of abnormal findings in carcinoma of the renal cyst wall is rare. However, cysts diagnosed via sonography which cannot be subjected to fine-needle biopsy, should be rechecked and followed up at regular intervals. If all possible methods of diagnosis are utilised (I.V. urography, sonography, fine-needle biopsy guided by sonography, computed tomography, angiography), successful differential diagnosis of localised pathological conditions of the kidneys can be achieved in 97% of all cases. Patient risk and cost of diagnosis can be kept at a minimum by proceeding in steps as described in the article. Primary surgical exposure of the kidneys in case of a cystic renal process would now appear justified for therapeutic reasons only, not for the purpose of arriving at a diagnosis.

Somatic embryogenesis and plant regeneration from leaf explants and cell suspensions of Solanum melongena (eggplant)

High frequencies of somatic embryogenesis evaluated on the basis of average embryo yield per explant were observed on leaf explants of Solanum melongena (L.) (eggplant) after 21 days of culture on a modified Murashige and Skoog medium. Callus proliferation and embryogenesis occurred in the presence of 1-naphthaleneacetic acid (NAA), whereas only callus induction occurred in the presence of the other auxins. Maximal embryo yields were obtained at 10 mg/L NAA. Although cytokinins inhibited the NAA-induced embryogenic response, they acted synergistically to promote callus growth. The frequency of embryogenesis on leaf explants was shown to be under the control of the nitrogen content of the medium. Both NH4+ and NO3− were essential for embryogenesis and an optimal ratio of 2:1 (NO3−:NH4+) was established. The optimal sucrose concentration of the medium was 0.06 M and both elevated and reduced sucrose levels inhibited embryogenesis. Seven cultivars showed significant quantitative differences in their capacities to form embryos, although all were embryogenic. Cell suspension cultures were also embryogenic, when grown under conditions which stimulated embryogenesis in leaf explants. Somatic embryos taken from leaf callus or cell suspensions and cultured on hormone-free medium gave rise to plants which set seed when transferred to the greenhouse. Shoot organogenesis was observed on leaf explants which were cultured in the presence of either of four cytokinins. Shoots were rooted on hormone-free medium and mature plants were subsequently obtained.

Transcription and processing of adenoviral RNA by extracts from HeLa cells

Concentrated extracts from HeLa cells prepared by the procedure of Sugden and Keller [Sugden, B. & Keller, W. (1973) J. Biol. Chem. 248, 3777-3788] can synthesize RNA molecules of discrete lengths in the presence of DNA templates carrying complete viral transcription units. Accurate initiation of transcription was shown to occur at the "major late" promoter and at the promoter for the "early region III" transcription unit of the adenovirus 2 genome. A cloned fragment of adenovirus 2 DNA containing the early region III transcription unit directs the synthesis of discrete RNA species, many of which correspond in length to spliced early region III mRNAs isolated from adenovirus 2-infected HeLa cells. As shown by hybridization/nuclease S2 analysis, RNA splicing and the formation of specific 3' ends are also taking place in vitro.

Cloning of cDNA of major antigen of foot and mouth disease virus and expression in E. coli

Double-stranded DNA copies of the single-stranded genomic RNA of foot and mouth disease virus have been cloned into the Escherichia coli plasmid pBR322. A restriction map of the viral genome was established and aligned with the biochemical map of foot and mouth disease virus. The coding sequence for structural protein VP1, the major antigen of the virus, was identified and inserted into a plasmid vector where the expression of this sequence is under control of the phage lambda PL promoter. In an appropriate host the synthesis of antigenic polypeptide can be demonstrated by radioimmunoassay.

Nucleotide sequence analysis of the leader segments in a cloned copy of adenovirus 2 fiber mRNA

Fiber mRNA of adenovirus 2 has been used as a template for RNA-dependent DNA polymerase. The resulting cDNA/RNA hybrids have been inserted at the Pst I site of the plasmid vector pBR322 after A:T tailing. One recombinant plasmid, pJAW 43, has been characterized in detail and shown to contain sequences from the main body of fiber mRNA, the three leaders common to most late adenoviral mRNAs and a fourth leader found in some species of fiber mRNA. The complete DNA sequence of the leader region has been determined and does not contain the initiation codon AUG, although this codon does occur immediately downstream from the junction between the fourth leader and the main body of the fiber mRNA. The first leader (map coordinate 16.6) is 41 nucleotides long, the second (from 19.6) is 71 nucleotides, the third (from 26.6) is 88 nucleotides and the fourth (from 78.5) is 181 nucleotides. The location of junctions between viral leaders and intervening sequences has been determined by reference, where possible, to sequences of the adenovirus 2 genome. Although the presence of short repeated sequences at the boundaries of intervening sequences and leaders makes it impossible to locate the splice point unambiguously, all of the leader-intervening sequence junctions can be arranged to stress a common feature--the presence of the dinucleotides GT and AG at the 5' and 3' ends, respectively, of the intervening sequences. This prototype sequence, which has also been recognized at or near the splice points in other eucaryotic systems, is possibly part of a larger unit which serves as a recognition site for specific excision-ligation events that ultimately lead to the production of mature mRNAs.

Treatment of demyelinating and degenerative diseases by electro stimulation of the spinal cord

Electrical stimulation was applied to the spinal cord of 75 patients who had demyelinating and degenerative diseases of the central nervous system, and 3 patients who had sustained spinal cord injuries. The electrical energy was delivered to the central nervous system by the percutaneous technique. The amount of electrical energy required to produce the perception of paresthesias was measured in 11 patients. The minimum power necessary was 76.89 muW, the maximum was 868 muW, and the average was 448.8 muW. The patients were evaluated by 4 examiners by means of routine neurologic examination, videotape movies, and measurement of urinary bladder function. Continued improvement in neurological status, which allowed the patient to live a better lifestyle, occurred in 30 of the 61 patients with multiple sclerosis, and 6 of the 10 patients with ataxia. The patient with transverse Myelitis, the patient with primary lateral sclerosis, and 1 patient with olivopontocerebellar atrophy; also noted similar enhancement of neurological function. The patients with amyotrophic lateral sclerosis and spinal cord injuries had no changes of significance. Thirty-two out of 44 patients who were ambulatory had significant improvement, whereas 10 of the 19 patients who were not ambulatory had improvement. There was no evidence that electrical stimulation of the spinal cord, when applied via dorsally placed percutaneous electrodes and when carried only to the perception of a paresthesias, has any adverse effect on neurological function. It is hypothecated that the electrical current alters neurotransmitters to enhance the transmission along nervous and neurochemical pathways. The exact mechanisms are unknown at the present time.

Higher order structure of simian virus 40 chromatin

Simian virus 40 nucleoprotein complexes undergo an ionic strength-dependent structural transition. At moderate ionic strength they contain histone H1 as well as the nucleosomal histones and have a compact conformation with globular subunits 190 angstroms in diameter. At high ionic strength histone H1 is released, and the structure unfolds into chains with an average of 24 nucleosomes. The extended viral chromatin converts to the compact form by the addition of histone H1. Transcriptionally active simian virus 40 chromatin undergoes the same structural transitions. The higher order structure of viral chromatin may be analogous to the compact state of cellular chromatin fibers observed at physiological ionic strength.

[Postoperative feeding of patients after maxillofacial surgery with Sokoham--a new parenteral nutritive solution]

20 patients--15 to 71 years old--, who underwent maxillofacial operations received Sokoham for 10 days via a nasogastric tube. In 0.8% of all applications vomiting occurred. Wound healing and time of hospitalisation were the same as in a control group. Mean frequency of defecation was 0.5/24 hours. Body weight, serum electrolytes, fat content of the blood, blood gases, pH, base deficit, serum transaminases, urea-nitrogen and creatinine in the serum did not change significantly.

The structure of SV 40 chromatin

Simian virus 40 (SV40) nucleoprotein complexes were studied with the electron microscope. Depending on the isolation procedure, SV40 chromatin has two different conformations: complexes isolated in the presence of 0.15 M NaCl appeared as very compact globular structures, while those isolated in the presence of 0.6 M NaCl had the typical 'beads-on-a-string' appearance of the primary nucleofilament. Concomitant with this structural change was a variation in the histone pattern and sedimentation behaviour of the complexes: with NaCl at 0.15 mol 1(-1) the isolated complexes contained both the nucleosomal histones and histone H1, and sedimented in sucrose gradients at 70S. Increasing the ionic strength to 0.6 M NaCl resulted in the removal of histone H1 from the complexes and in a decrease of the sedimentation coefficient to 40S. DNA relaxing enzyme is associated with the SV40 nucleoprotein complexes. The numbers of superhelical turns in DNA from compact and open types of complexes were found to be the same. Therefore the transition from the condensed to the open structure of viral chromatin does not require a change in the topological winding number of its DNA.

Postoperative Ernährung kieferchirurgischer Patienten mit Sokoham^® – einer neuen Sondennahrung

20 Patienten im Alter von 15 bis 71 Jahren, die sich kieferchirurgischen Operationen unterzogen, wurden über einen Zeitraum von zehn Tagen mit der Sondenfertignahrung Sokoham^® ernährt. Bei einer Flüssigkeitszufuhr von 1,0-2 1/24 h wurden pro Tag im Mittel 1000–2000 ml Sokoham^® (= 1600 – 3200 kcal) bolusartig appliziert. Sokoham^® wurde in insgesamt 735 Portionen gegeben. 6mal (= 0,8 %) trat nach der Sokoham^®-Gabe Erbrechen auf. Die Häufigkeit der entleerten Stühle lag im Mittel bei 0,5/Tag/Patient. Die Zahl der Wundheilungsstörungen und die Dauer des Krankenhausaufenthaltes unterschieden sich bei den mit Sokoham^® ernährten Patienten nicht von einer Kontrollgruppe von Patienten, die mit anderer Sondennahrung ernährt wurde. Das Körpergewicht änderte sich nicht signifikant. Die Elektrolyte Natrium, Kalium und Kalzium zeigten mit Ausnahme des Natriums zu Beginn subnormale Werte oder Konzentrationen im unteren Normbereich und normalisierten sich im weiteren Verlauf der Ernährung. Arterielle Blutgase, Parameter des Säure-Basen-Haushaltes, harnpflichtige Substanzen im Serum, Serumtransaminasen, alkalische Phosphatase, Fettstoffwechsel und der Gesamteiweiβgehalt im Serum ließen keinen signifikanten Einfluß der Sokoham^®-Ernährung erkennen. Die anfangs erniedrigten Hb- und Hkt-Werte zeigten eine Tendenz zur Normalisierung.

Biochemical and ultrastructural analysis of SV40 chromatin

SV40 chromatin can be isolated in two forms: At moderate ionic strength (mu = 0.1-0.3) it contains histone H1 in addition to the four nucleosomal histones and has a highly condensed appearance in the electron microscope, being composed of a few closely connected large spheres [190 A (160, 220) diameter]. At high ionic strength (mu = 0.6-0.8) or after prolonged exposure to very low ionic strengths (mu less than 0.02), the compact form unfolds and the chromatin shows a typical nucleosomal morphology. Native SV40 DNA-protein complexes contain a median number of 24 nucleosomes. The number of superhelical turns does not differ in DNA obtained from the compact and the unfolded forms of chromatin. DNA-relaxing enzyme is found associated with SV40 chromatin and is capable of acting both on extraneously added circular DNA and on its own DNA in the nucleoprotein complex. Purified DNA-relaxing enzyme forms transiently nicked DNA intermediates where the enzyme can be found covalently attached to the site of the nick in the DNA. Transcriptionally active SV40 complexes undergo the same ionic-strength-dependent structural transition as that of bulk SV40 chromatin and may therefore also have a compact configuration at physiological salt concentrations.

[Experimental investigations on the tumorigenic activity of cigarette smoke condensate on mouse skin. VII. Comparative studies of condensates from different modified cigarettes (author's transl)]

Condensate from different modified cigarettes were compared with condensate from a standard cigarette with regard to its tumorigenic activity on mouse skin. Significant lower effects were observed in test series with cigarettes from expanded tobacco. Different results were obtained in experiments with cigarettes from the new smoking materials. In one case the effect was higher, in two another cases the effect was lower in comparison to the effect of condensate from reference cigarettes. A certain influence may be referred to the diameter of the cigarette, i.e. a thinner cigarette shows a lower biological effect. The lowest tumoringenic effect was observed in tests with cigarettes with a high content of Burley-stems.

The presentation and use of height and weight data for comparing the nutritional status of groups of children under the age of 10 years

This paper presents recommendations for the analysis and presentation of height and weight data from surveillance or surveys involving nutrition and anthropometry in young children up to the age of 10 years. These recommendations are only for the analysis of data collected on a cross-sectional basis. The basic indices recommended are height for age and weight for height, each considered either in terms of centiles or in a cross-classification scheme using standard deviation scores. It is hoped that these methods of analysis and presentation will prove widely acceptable, so that international comparisons will be made easier.

Genes inhibiting senescence in the ascomycete Podospora anserina

Senescence occurs in all wild strains of Podospora anserina after continued growth. This syndrome can be inhibited by a synergistic interaction of two linked genes, incoloris and vivax. Whereas the wild strain starts to become senescent after 26 d and the mutants incoloris and vivax after 42 and 66 d respectively, the double mutant shows no signs of aging after culture for more than one year.