Lichens toGunnera — with emphasis onAzolla

Summary N₂-fixing cyanobacteria occur in symbiotic associations with fungi (ascomycetes) as lichens and with a few green plants. The associated cyanobacterium is always a species ofNostoc orAnabaena. Only a small number of plant genera are involved but there is a remarkable range of host diversity. Associations occur with several bryophytes (e.g.Anthoceros, Blasia, Cavicularia), a pteridophyte (Azolla), cycads (nine genera includingMacrozamia andEncephalartos) and an angiosperm (Gunnera). Except forGunnera, where the cyanobacterium penetrates the plant cells, the cyanobacteria are extracellular with specialized morphological modifications and/or structures of the host plant organs providing an environment which facilitates interaction with the prokaryote.Salient aspects of current knowledge pertaining to the establishment, perpetuation, and functioning of the individual symbioses are summarized. Where possible this includes information concerning recognition and specificity, mode(s) of infection, morphological modifications/adaptations of the host plant and a synopsis of morphological, physiological and biochemical changes common to the symbiotic cyanobacteria. The latter encompasses heterocyst frequencies, enzymes involved in ammonia assimilation, photosynthetic capability and metabolic interaction with the host.TheAzolla-Anabaena symbioses, which have potential agronomic significance as an alternative nitrogen source and maintain continuity with the endophyte through the sexual cycle, are emphasized.     

MSCs—cells with many sides

The field of mesenchymal stromal cell (MSC) biology and clinical cellular therapy has grown exponentially over the last few decades. With discovery of multiple tissue specific sources of stromal cells, invariably being termed MSCs, and their increasing clinical application, there is a need to further delineate the true definition of a mesenchymal stromal cell and to recognise the inherit differences between cell sources; both their potential and limitations.In this review, we discuss the importance of considering every stromal cell source as an independent entity and the need to critically evaluate and appreciate the true phenotype of these cells and their safety when considering their use in novel cell therapies.     

COCCIDIOIDOMYCOSIS—Treatment with Isonicotinic Acid Hydrazide

Since coccidioidal granulomas are histologically indistinguishable from tuberculous granulomas, a long course of isonicotinic acid hydrazide therapy was tried experimentally in three cases of coccidioidomycosis, with good results. In two cases the disease was far advanced and prognosis poor before INH therapy was begun. In one case the disease was mild and symptoms abated after a short course of small doses of INH. It recurred when INH therapy was discontinued, and again resolved when larger doses of INH were given over a longer period.INH seemed to have an effect on appetite also, although the patients were taking B-complex vitamins both before and during INH treatment. The three patients ill with coccidioidomycosis averaged a weight gain of four and a half pounds a month during the period of INH therapy. Six well persons who were underweight and lacked appetite were given INH without other drugs, and they then had an increase in appetite and in weight.     

Galanin—A neuropeptide with inhibitory actions

Summary 1. Galanin is a 29 (in humans 30) amino acids long neuropeptide with mostly inhibitory, hyperpolarizing actions.2. Differential structural requirements of truncated forms of galanin and differential agonist/antagonist behaviour of chimeric peptides, high affinity galanin receptor ligands suggest the presence of pharmacologically distinct galanin receptor subtypes.3. The galanin receptor from human Bowes melanoma cell line—a member of G-protein coupled receptor superfamily—has been cloned.4. Galanin acts via G_i/G_o proteins inhibiting cAMP production, inositol phosphate turnover, opening K⁺ channels or closing Ca²⁺ channels.     

That's A Scientist Should Do——A Dialog with Tomas Lindahl

正Dr Tomas Lindahl is a world-renowned scientist specialized in cancer research,in particular,DNA repair [1].In 2015,he was awarded the Nobel Prize in Chemistry jointly with Dr Paul L.Modrich and Dr Aziz Sancar ‘‘for mechanistic studies of DNA repair"(https://www.nobelprize.org/prizes/chemistry/2015/press-release/)[2].During his recent visits in China,besides delivering lectures,Tomas also attended a couple of group meetings with students and PIs.He actively interacted with the audience,not only on topics relating to DNA repair,but also on how to do science and beyond.We presented this special report based on recordings.     

ACROMIOCLAVICULAR DISLOCATIONS—Open Reduction with Screw Fixation

Athletes with complete separation of the acromioclavicular joint were uniformly restored to full athletic competence by an operation consisting of direct repair of the involved ligamentous structures with temporary fixation by a metallic lag screw approximating the clavicle to the coracoid. The metallic fixation was left in place an average of eight weeks and the screw was then removed under local anesthesia. A number of professional and collegiate football players returned to the rigors of football with no discomfort or disability.     

Roberts' — SC phocomelia syndrome with cytogenetic findings

Summary This paper reports the physical and cytogenetic findings in an eight-year-old severely mentally retarded female child with the following features: tetraphocomelia; weight, lenght, and head circumference below the third percentile; microcephaly with prominent frontal bones; hypertelorism; shallow orbits; prominent eyes; bilateral corneal opacities; micrognathia; hypoplastic alae nasi; small, low set ears; short neck; sparse silvery blond hair; severe flexion deformities of both knees and wrist joints; a cardiac murmur. Cytogenetic studies revealed premature centromere separation.     

Orotidine Monophosphate Decarboxylase——A Fascinating Workhorse Enzyme with Therapeutic Potential

Orotidine 50-monophosphate decarboxylase(ODCase) is known as one of the most proficient enzymes. The enzyme catalyzes the last reaction step of the de novo pyrimidine biosynthesis, the conversion from orotidine 50-monophosphate(OMP) to uridine 50-monophosphate. The enzyme is found in all three domains of life, Bacteria, Eukarya and Archaea. Multiple sequence alignment of 750 putative ODCase sequences resulted in five distinct groups. While the universally conserved Dx Kxx Dx motif is present in all the groups,depending on the groups, several characteristic motifs and residues can be identified. Over 200 crystal structures of ODCases have been determined so far. The structures, together with biochemical assays and computational studies, elucidated that ODCase utilized both transition state stabilization and substrate distortion to accelerate the decarboxylation of its natural substrate. Stabilization of the vinyl anion intermediate by a conserved lysine residue at the catalytic site is considered the largest contributing factor to catalysis, while bending of the carboxyl group from the plane of the aromatic pyrimidine ring of OMP accounts for substrate distortion. A number of crystal structures of ODCases complexed with potential drug candidate molecules have also been determined, including with 6-iodouridine, a potential antimalarial agent.     

Immunoscintigraphy with biosynthetically-labeled 75Se-antibodies—II. Comparison with antibodies labeled by radioiodination

The biodistributions of ⁷⁵Se and ¹²⁵I were compared in nude mice bearing melanomas and injected simultaneously with biosynthetically-labeled ⁷⁵Se-MoAbs and radioiodinated ¹²⁵I-MoAbs from the same anti-melanoma hybridoma. The ⁷⁵Se dose recovery in the tumor (day 10) was twice that for ¹²⁵I, but the tumor to normal tissue ratios were identical. It is concluded that biosynthetically-labeled MoAbs survive better in vivo, while the tumor to normal tissue ratios are governed by the excretion rate of labeled MoAb catabolytic products.     

Cholesterol's interactions with serine phospholipids — A comparison of N-palmitoyl ceramide phosphoserine with dipalmitoyl phosphatidylserine

In this study we have prepared ceramide phosphoserine (CerPS) and examined its sterol-interacting properties. CerPS is a hydrogen-bonding sphingolipid, but its head group differs from that found in sphingomyelin (SM). Based on diphenylhexatriene steady-state anisotropy measurements, we observed that fully hydrated N-palmitoyl CerPS had a gel-to-liquid crystalline phase transition temperature of about 51 °C in 50 mM sodium phosphate buffer (pH 7.4). This was close to the T_m measured for 1,2-dipalmitoyl-sn-glycero-3-phosphoserine (DPPS) bilayers (T_m 50.5 °C). Based on cholestatrienol (CTL) quenching experiments in liquid disordered ternary bilayers (containing 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphcholine; POPC), cholesterol/CTL formed sterol-enriched ordered domains with CerPS. These had similar thermostability as the sterol domains formed with N-palmitoyl SM. Cholesterol failed to form sterol-enriched ordered domains with DPPS under comparable conditions. Based on the equilibrium partitioning of CTL, we observed that the affinity of sterol for bilayers containing POPC/CerPS/cholesterol (6:3:1 by mol) was much higher than the affinity measured for control fluid POPC/cholesterol (9:1 by mol) bilayers, but slightly less than seen for comparable PSM-containing bilayers. We conclude that the phosphoserine head group was less efficient than the phosphocholine head group in stabilizing sterol/sphingolipid interaction. However, hydrogen bonding apparently can overcome some of the negative effects of the phosphoserine head group, since CerPS interacted more favorably with cholesterol compared to DPPS.     

Laminin-121—Recombinant expression and interactions with integrins

Laminin-121, previously referred as to laminin-3, was expressed recombinantly in human embryonic kidney (HEK) 293 cells by triple transfection of full-length cDNAs encoding mouse laminin α1, β2 and γ1 chains. The recombinant laminin-121 was purified using Heparin-Sepharose followed by molecular sieve chromatography and shown to be correctly folded by electron microscopy and circular dichroism (CD). The CD spectra of recombinant laminin-121 were very similar to those of laminin-111 isolated from Engelbreth-Holm-Swarm tumor (EHS-laminin) but its T_m value was smaller than EHS-laminin and recombinant lamnin-111 suggesting that the replacement of the β chain reduced the stability of the coiled-coil structure of laminin-121. Its binding to integrins was compared with EHS-laminin, laminin-3A32 purified from murine epidermal cell line and recombinantly expressed laminins-111, -211 and -221. Laminin-121 showed the highest affinity to α6β1 and α7β1 integrins and furthermore, laminin-121 most effectively supported neurite outgrowth. Together, this suggests that the β2 laminins have higher affinity for integrins than the β1 laminins.     

Coccidioidal Meningitis—Intrathecal Treatment with Hyperbaric Amphotericin B

The localization of coccidioidal meningitis in the basilar regions, with resultant hydrocephalus and uniformly fatal outcome, has necessitated intrathecal injection of amphotericin B via cisternal puncture or subcutaneous ventricular reservoir for successful therapy. A simpler form of treatment is described here, whereby amphotericin B diluted in 10 percent glucose solution is injected via lumbar puncture, and delivered to the base of the skull by tilting the patient to a head-down position. A simultaneously performed hyperbaric cisternogram with ¹³¹I-serum albumin has demonstrated satisfactory migration of the injected bolus to the occiput. This method of administration resulted in successful suppressive treatment of one patient, including two years of follow-up without serious sequelae or relapse.     

RENOGRAMS—Correlation with Renal Arteriography and Intravenous Pyelography

A study was carried out to determine how well the information supplied by a radioactive renogram correlates with that obtained by renal arteriography and intravenous pyelography. In 1962 35 patients at the UCLA Medical Center had all three studies. This represents a total of 70 kidneys (one kidney surgically absent). We found the radioactive renogram to be a very reliable and valuable aid in the diagnosis of kidney disease. When compared with the results of the intravenous pyelogram and aortogram, the renogram had false negative result in 11 per cent of cases, and a 14 per cent false positive result.     

An Empirical Potential Study of the Interaction of L—;Lysine—;L—;Alanine—;L—;Alanine Tripeptide with Four models of B—;DNA with different Compositions

Abstract

The empirical potential including the intra- and intermolecular energy terms was used to study the interaction of L-Lysine-L-Alanine-L-Alanine Tripeptide with four models of B-DNA with different compositions. On the basis of a detailed search of the respective potential energy surface, it was found that the peptide is preferentially bounded to the AT-rich sequences. Analysis of the different energy contributions indicated that the electrostatic term is responsible for this preference. The results agree with the experimental data on the selectivity of some DNA—binding proteins and polypeptides to AT—;rich DNA.     

CHOLANGIOGRAPHY AFTER CHOLECYSTECTOMY—Visualization with Cholografin by Vein

A new drug, Cholografin, makes visualization of the bile ducts (hepatic, cystic and common) clinically available.