Molecular recognition and binding of a GC site-avoiding thiazole-lexitropsin to the decadeoxyribonucleotide d-[CGCAATTGCG]2: 1H-NMR evidence for thiazole intercalation

The structural and dynamic aspects of the interaction of the thiazole containing lexitropsin (1) with an oligodeoxyribonucleotide were studied by high field 1H-NMR spectroscopy. Complete assignment of the 1H-NMR resonances of lexitropsin 1 was accomplished by 2D-NMR techniques. The complexation-induced chemical shifts and NOE cross peaks in the NOESY map of the 1:1 complex of lexitropsin (1) and d-[CGCAATTGCG]2 reveal that the thiazole ring of the lexitropsin (1) intercalates between dA4.A5 bases and the rest of the ligand resides in the minor groove of the AT rich core of decamer, thus occupying the 5'-AATT sequence on the DNA. Intercalation of the thiazole moiety of the drug has been detected by the presence of intermolecular NOEs both in the major and the minor groove of the decamer helix. The absence of intranucleotide NOEs between base protons and H1'/H2' protons suggested local unwinding of the binding site on the DNA. From COSY and NOESY methods of 2D-NMR, it was established that the N-formyl (amino) terminus of the thiazole lexitropsin (1) is projecting into the major groove towards A5H8 while the amidinium terminus lies in the minor groove towards the T7G8 base pairs of the opposite strand. The expected intranucleotide NOEs confirmed that the decadeoxyribonucleotide in the 1:1 complex exists in a right handed B-conformation. The presence of exchange signals along the binding site 5'-AATT indicated an exchange of the bound drug process wherein the rate of exchange between the two equivalent sites was estimated to be congruent to 130 s-1 at 30 degrees C and with delta G degrees of 62.4 kJ mol-1. Force field and Pi calculations permitted a rationalization of the experimentally observed binding mode in terms of preferred conformation of the ligand and repeat length in lexitropsins compared with the DNA receptor.

[Tumoral calcinosis]

Tumoral calcinosis is a distinct entity, which is rarely seen in Europe and North America but much more common in black Africans. Typical symptoms are calcified nodules, which grow while remaining asymptomatic and are found in the tissues adjacent to the large joints of the body. Histologically there is collagen necrobiosis initially, which results in aggregates of densely calcified material. The aetiology is unknown, but the condition is probably a form of dystrophic calcification caused by mechanical injury. A patient with tumoral calcinosis is presented, and the clinical and histological findings are described.

Automated DNA sequencing of the human HPRT locus

The complete sequence of 57 kb of the human HPRT locus has been determined using automated fluorescent DNA sequencing. The strategy employed increasingly directed sequencing methods: A randomly generated M13 library was sequenced to generate contiguous overlapping sets of sequences (contigs). M13 clones at the ends of these contigs were further sequenced using M13 (universal and reverse) and custom oligonucleotide primers to order the contigs and to complete the sequencing project. The human HPRT sequence includes 1676 bp 5' and 15,238 bp 3' to exons 1 and 9, respectively. The sequence contains 49 representatives of the Alu repeat, along with several other types of repetitive sequences. The Alu sequences exhibit a biased orientation, with those sequences in the first half of the locus oriented in the minus direction relative to transcription of the gene (3'----5' = 77%, P less than 0.005) and those sequences in the latter half of the locus oriented randomly (5'----3' = 67%, P less than 0.5). The development and performance of the sequencing strategy and the features of the human HPRT gene are presented.

[Renal effects of ibopamine in comparison with furosemide in patients with mild heart failure]

Ibopamine is a novel oral dopamine analogue with positive inotropy and diuretic effects. In a double-blind, randomized study, the drug was investigated in 10 patients (mean age 49 +/- 10 years, six male, four female) with mild heart failure (NYHA classes II: six patients, III: four patients). Effects of single oral doses of 200 mg ibopamine, of 40 mg furosemide, and of 200 mg ibopamine plus 40 mg furosemide were compared in each patient at 3-day-intervals. One h after application, systolic and diastolic blood pressure increased from 119 +/- 11 to 124 +/- 8, and from 75 +/- 4 to 80 +/- 6 mm Hg (p less than 0.01) in the ibopamine group, while changes in both other groups and changes of the heart rate were insignificant. During 2 h after drug ingestion urinary flow was raised from 124 +/- 81 to 227 +/- 166 ml/2 h in the ibopamine group (p less than 0.05), while the application of furosemide (with or without ibopamine) resulted in several fold increases of urinary flow. After ibopamine, the 2-h-creatinine-clearance rose from 123 +/- 73 to 130 +/- 85 ml/min (not significant). Sodium excretion remained unchanged by ibopamine, potassium excretion was increased from 2.9 +/- 1.7 to 4.0 +/- 3.3 mmol/h (p less than 0.05), while effects of furosemide were several fold of those of ibopamine. Atrial natriuretic factor concentrations in plasma increased significantly after ibopamine and after ibopamine plus furosemide (p less than 0.01), but remained constant after furosemide alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Extracardial effects of oral ibopamine versus furosemide in patients with mild or moderate heart failure. A double-blind, randomized trial

Ibopamine is a novel oral dopamine analogue with vasodilatory, positive inotropic and diuretic effects. In a double-blind, randomized study, the drug was investigated in 12 patients (mean age 49 +/- 10 years, 8 male, 4 female) with mild or moderate heart failure (NYHA classes II:8 patients, III:4 patients). Effects of single oral doses of 200 mg ibopamine, of 40 mg furosemide and of 200 mg ibopamine + 40 mg furosemide were compared in each patient at 3-day intervals. 1 h after administration, systolic and diastolic blood pressure increased from 120 +/- 11 to 124 +/- 9 and from 76 +/- 5 to 81 +/- 6 mm Hg in the ibopamine group. During 4 h after drug ingestion, urinary flow was significantly raised from 124 +/- 81 to 228 +/- 166 ml/2 h in the ibopamine group (p less than 0.05), while the administration of furosemide (with or without ibopamine) resulted in several folds increases of urinary flow. After ibopamine, the 2-h creatinine clearance rose from 123 +/- 73 to 131 +/- 85 ml/min (not significant). Sodium and potassium excretion remained essentially unchanged by ibopamine, while effects of furosemide were several folds of those of ibopamine. Plasma renin activity was lowered to 65% by ibopamine (p less than 0.01). No additive effects of ibopamine in the presence of furosemide were observed for all parameters tested. These results indicate that ibopamine has smaller renal effects than furosemide with regard to water diuresis and kaliuresis. These effects of ibopamine could reflect direct changes of renal function or secondary effects of neurohumoral origin. Ibopamine does not produce undesirable renal side effects, but affects the neurohumoral status favourably. This drug, thus, could be useful as an adjuvant therapy in mild heart failure.

Automated sequencing of fluorescently labelled DNA by chemical degradation

A new general method for sequencing fluorescently labelled DNA by chemical degradation has been developed. It is based on the observation that fluorescein attached via a mercaptopropyl or aminopropyl linker arm to the 5'-phosphate of an oligonucleotide is stable during the reactions commonly used in chemical cleavage procedures. DNA to be degraded is first enzymatically synthesized in vitro by annealing and extending a fluorescently labelled primer thereby introducing the fluorescent label at the 5'-end of the fragment. The newly synthesized fluorescently labelled DNA is then chemically degraded using: (a) a set of four different cleavage reactions; or (b) only one reaction comprising methylation of G-residues followed by a partial cleavage with piperidine in the presence of sodium chloride. The fluorescent degradation products are loaded on either four lanes or one lane of the gel, respectively, and the emitted fluorescence detected online during electrophoresis. In the 'four reactions/four lanes' method 200-350 bp (base pairs) can be read from the labelled end. The 'one reaction/one lane' method, in which the nucleotide sequence is determined by measuring different signal intensities following the rule G greater than A greater than C greater than T, currently yields around 100-200 bp of sequence per sample.

Direct genomic fluorescent on-line sequencing and analysis using in vitro amplification of DNA

In vitro amplification of genomic DNA and total RNA, as well as recombinant DNA, using one fluorescently labelled and one unlabelled primer during amplification, together with on-line analysis of the products on the EMBL fluorescent DNA sequencer, is described. Further is reported direct sequencing of fluorescently labelled amplified probes by solid-phase chemical degradation, without subcloning and purification steps involved. At present up to 350 bases in 4 hours are determined with this technique. The fluorescent dye and its bond to the oligonucleotide are stable during the amplification cycles, and do not interfere with the enzymatic polymerization. High sensitivity of the detection device, down to 10(-18) moles, corresponding to less than 10(6) molecules makes possible analyses of the non-radioactive amplified probes after only 10 amplification cycles, starting with about 5 x 10(4) copies of recombinant DNA.

Automated Sanger DNA sequencing with one label in less than four lanes on gel

Novel Sanger dideoxy sequencing with only one fluorescent dye label for the four bases of one clone and sequence determination in two lanes on polyacrylamide gel is presented, loading A greater than G in one lane and T greater than C in the other. Sequencing reactions for the two bases in each lane are carried out in one tube. At present the ratio of ddATP:ddGTP and ddTTP:ddCPT is set to 5:1 in the two tubes. Distinction between the two bases in one lane is done by comparing the different magnitudes of the peaks. This method increases the capacity since more clones may be run simultaneously on one gel, while keeping the reliability and simplicity that comes with the use of only one fluorescent dye for the four bases of one clone. At present about 200 bases are determined with the one-dye two-lane method on the EMBL's automated fluorescent DNA sequencer, using T7 DNA polymerase. The error rate in the deduced sequence is about 1%. The technique is used for the determination of overlaps in mapping projects. In principle, it is possible to determine the sequence with one dye in only one lane on the gel by choosing the proper ddNTP ratios for all four bases, carrying out reactions in one tube and applying the product in one lane, but the error rate for this one-lane method seems too high at present and further improvements in the uniformity of peaks obtainable with the T7 DNA polymerase or other enzymes are required.

Oligoclonal bands in serum and cerebrospinal fluid of patients with HIV infection

Matched samples of serum and cerebrospinal fluid (CSF) from 15 human immunodeficiency virus (HIV)-infected patients were examined after isoelectric focusing. The appearance of oligoclonal bands only in the CSF could indicate the primary HIV infection of CNS in early stages of the disease. Later, the increasing number of autochthonous oligoclonal bands in the CSF suggested locally synthesized IgG against opportunistic infections. Because of the immunodeficiency, T cell independent polyclonal B cell stimulation might mask the oligoclonal pattern.

Automated Sanger dideoxy sequencing reaction protocol

The protocol for Sanger dideoxy chain termination reactions in DNA sequencing is tedious and prone to errors due to the repetitive character of the pipetting steps. An industrial robot, with the addition of a few simple parts, was programmed to automate the dideoxy sequencing reactions. The system is set up in a short time for routine operation and it is faster and more reliable than a human operator. It is flexible and allows variations and optimization of the standard procedure. Disposable microtiter plates at a controlled temperature are used. In one reaction cycle (about 50 min) up to 48 templates are processed. Up to 450 bases were resolved in automated DNA sequencing on samples prepared by the robot. The protocol is applicable to fluorescent as well as to radioactive labeling.

Characteristics of cellular immune responses to collagen type I or collagen type II

We have examined the murine cell-mediated immune (CMI) response to collagens type I (CI) and type II (CII) as measured by in vivo delayed-type hypersensitivity responses. We have verified the histopathology and kinetics of the cell-mediated immune responses. Predominant cell-mediated responses were obtained 7, 10, or 14 days following immunization. A presumed antibody-mediated reaction was observed at later times (e.g., greater than 21 days following immunization). The CMI responses to the collagens show a strain-dependent relationship. For CI, the CMI response profile shows H-2b greater than or equal to H-2k = H-2q much greater than H-2d. For bovine CII, the response profile is H-2d greater than H-2b = H-2k = H-2q; the chick CII response profile is H-2q = H-2k greater than H-2b = H-2d, and in limited testing, only the H-2q strain could generate murine CII-specific cell-mediated immune responses. The CII-specific CMI response is cross-reactive with CII from several species of animals, but not with CI. Further, the collagen-specific CMI response can be elicited with certain cyanogen-bromide fragments of bovine CII. Finally, our study also demonstrates that there is a non-H-2-linked locus(i) involved in the development of CII-induced arthritis.

Adrenergic regulation of sodium and chloride transport in the isolated cornea of rabbit and man

Isolated corneas were mounted in Ussing-Zerahn-type chambers and short circuit current (SCC) was measured before and after application of drugs (5 X 10(-5) mol X 1(-1)) interfering with adrenergic receptors. Epinephrine increased SCC in the rabbit cornea and decreased SCC in the human cornea. alpha-Adrenergic stimulation or inhibition did not affect SCC. The increase in SCC observed after terbutaline (beta 2-agonist) was similar to the increase after isoproterenol (beta 1- and beta 2-agonist). SCC was not influenced by the beta 1-antagonist atenolol but was modified, although differently in rabbit and man, by the beta 1- and beta 2-antagonist propranolol. Thus, the catecholamine response of the rabbit and human cornea is mainly mediated by beta 2-adrenergic receptors. However, species differences were observed when testing the effect of propranolol on the transcorneal flux of 22Na and 36Cl. In the rabbit cornea the net Cl flux (directed from the aqueous to the tear side) was inhibited by propranolol, whereas net Na flux (from the tear to the aqueous side) was not influenced by the drug. In the human cornea propranolol reduced unidirectional Na flux from the aqueous to the tear side. Thus, the regulatory effect of propranolol on corneal transparency is different in man and the rabbit.

Ribosomal recessive suppressors cause a respiratory deficiency in yeast Saccharomyces cerevisiae

Recessive suppressor mutations in yeast Saccharomyces cerevisiae alter a component of the cytoplasmic ribosomes, relaxing the control of translational fidelity. As a consequence ribosomes can misread nonsense codons as amino acids (Surguchov et al. 1980a). The suppressor mutants are often respiratory deficient, being unable to grow on non-fermentable substrates. The study of the cytochrome spectra has revealed that the cytochrome b and aa3 contents were lower in the mutants than in the parent strains. Furthermore, the suppressor mutations often cause hypersensitivity to paromomycin and neomycin on media with a non-fermentable source of carbon. Some of the suppressor mutants exhibited both erythromycin and chloramphenicol-dependent growth on media containing ethanol or glycerol as a sole carbon source. These results suggest that the mutations altering cytoplasmic ribosomes may simultaneously impair the mitochondrial translation. A coupling of cytoplasmic and mitochondrial protein synthesis in yeast cells is proposed. The existence of a common protein component participating both in mitochondrial and cytoplasmic protein synthesis apparatus is discussed.

High-power phosphate-glass laser system: design and performance characteristics

A one-beam prototype of a large twenty-four-beam phosphate-glass laser system has been built and tested. Basic design characteristics include Nd-doped phosphate glass, rod amplifiers up to 90-mm diam, the propagation of a circularly polarized beam, extensive spatial filtering and imaging, and the use of large-aperture Pockels cells. The prototype system has demonstrated focusable power in excess of 750 GW/beam at 50-psec full width at half-maximum (FWHM) pulse duration and has delivered 165 J of focusable energy in a 500-psec (FWHM) pulse. Maximum beam brightness has been measured to be 4 x 10(19) W/cm(2) .sr at a firing rate of 2 shots/hr. Peak-to-background energy contrast of 10(8) has been achieved with this system. A detailed description of the system design and performance is presented.

Prevention of necrosis in island myocutaneous flaps in the pig by treatment with isoxsuprine

Experimental gracilis myocutaneous flaps were designed in the pig which consistently resulted in 81 cm2 of surviving tissue and 194 cm2 of necrotic tissue. When these same flaps were raised in animals treated for two weeks preoperatively and 6 days postoperatively with isoxsuprine, there was 100 percent survival in all (8) flaps.

Prevention of muscle necrosis in an experimental neurovascular island muscle flap by a vasodilator drug--isoxsuprine

We report an experiment that demonstrates one means to prevent necrosis in an experimental island muscle flap. The results imply that necrosis of skeletal muscle in a clinical flap could be prevented by treatment with isoxsuprine.

Binding sites of E. coli and B. stearothermophilus ribosomal proteins on B stearothermophilus 5S RNA

The primary binding sites for Bacillus stearothermophilus proteins B-L5 and B-L22 and the Escherichia coli proteins E-L5, E-L18 and E-L25 on B. stearothermophilus 5S RNA were determined by limited ribonuclease digestion of the corresponding 5S RNA-protein complexes. The results obtained in this study are in agreement with our previous experiments in which the binding sites of E. coli and B. stearothermophilus proteins were determined for E. coli 5S RNA and lead to the conclusion that the proteins interact with the most conserved regions of 5S RNA. A comparison of the results obtained in this study with those of other published experiments suggest that the proposed interaction of nucleotides 16-21 with those of 58-63 is facilitated by protein binding to 5S RNA.