Hemoglobinopathies in the Hamilton region. II. Thalassemia traits and iron therapy.

Between July 1973 and July 1974 all adult patients with hypochromic anemia and a mean corpuscular volume of 75 mum3 or less were screened for hemoglobinopathies. Of the 490 patients 105 had beta-thalassemia trait, 11 had alpha1-thalassemia trait, 4 had hemoglobin Lepore trait and 1 had hemoglobin H disease. Of 48 inpatients whose charts were reviewed 19 had been on oral iron therapy and 7 of them had been given iron intramuscularly. Of 27 outpatients interviewed 10 had been on intermittent iron therapy for 18 months or more; 4 had been given at least 1 g of intramuscular iron. Iron deficiency was not documented in any of these patients. Iron deficiency should be diagnosed by means other than the presence of a hypochromic picture in the peripheral blood before iron therapy is instituted, particularly in communities with a large population of Mediterranean or South-East Asian origin.     

Synthetic analogues of polynucleotides. (Part) XIV. The synthesis of poly (3''-0-carboxymethyl-2''-deoxycytidine) and its interaction with polyinosinic acid.

Poly (3'-O-carboxymethyl-2'-deoxyctidine) (VII) has been synthesised by the polymerisation of 3'-O-carboxymethyl-4-N-phenoxyacety-2'-deoxycytidine (V) and removal of the phenoxyacetyl groups under acidic conditions. V was obtained by the action of 2,4-dinitrophenyl phenylacetate on 3'-O-carboxymethyl-5'-O-triphenylmethyl-2'-deoxycytidine (III) followed by removal of the triphenylmethyl group under carefully controlled acidic conditions. The polymer, VII gave a hypochromic effect of about 20% at 250nm when mixed with poly (1) in 0.2Macetate, pH 5.0. It appeared, therefore, that a complex was formed. Upon heating a solution of this complex there was an initial decrease in optical density followed by a much larger increase to give a Tm of about 60 degrees. Attempts to form the 3'-O-carboxymethyl derivative of 4-N-phenoxyacetyl-5'-O-'triphenylmethyl-2'-deoxycytidine to give a shorter synthetic route to VII were not successful. 3'-O-Carboxymethyl-2'-deoxycytidine was obtained by removal of thetriphenylmethyl group from III. Attempts to polymerise this compound in concentrated aqueous solution with a water-soluble carbodiimide were not successful.     

Thermal perturbation differential spectra of ribonucleic acids. II. Nearest neighbour interactions.

Dinucleoside monophosphates are used here as models for studying sequence dependence of the hypochromic effect correlated with base stacking. It was shown that once the contribution due to the temperature dependent hydration change of the bases is substracted from the thermal perturbation difference spectra of dinucleoside monophosphates, the absorbance change of the dimer only due to unstacking of the bases could be obtained. In order to be able to use these corrected thermal perturbation difference spectra as models for studying nearest neighbour interactions in nucleic acids, it was necessary to normalize them to 100% unstacking of the bases. To perform this normalization, apparent thermodynamic parameters were extracted from the corrected transition curves by means of the two-state model.     

The value of parameters of iron metabolism in the differential diagnosis of anemias]

As a result of investigations into the diagnostic validity of selected haematologic-morphological and clinical-chemical test factors of iron metabolism in the diagnosis of hypochromic anaemia, the examined test faktora are differently evaluated as individual parameters and in their combination. 1. Haematocrit (PCV) is equal to the determination of haemoglobin concentration as a search parameter. 2. The number of reticulocytes, copper and zinc as well as caeruloplasmin have a separating effect as individual parameters on the examined classes of iron deficiency and tumour and infect anaemia. 3. Iron has no value as a individual parameter. It is only in combination with TEBK and the haematologic test factors that is has a diagnostic value. 4. In contrast, ferritin as an individual parameter is of primary importance and should be used extensively in the laboratory diagnosis of hypochromic anaemia. 5. TEBK and transferrin may be supposed to be equal in their diagnostic value. 6. When used in combination, haemoglobin, MCV, TEBK, Transferrin, and ferritin have effective separating function. They permit hypochromic anaemia to be widely assigned to one or another kind of the examined classes.     

Deciphering binding affinity,energetics, and base specificity of plant alkaloid Harmane with AT and GC hairpin duplex DNA

Insights into binding efficacy and thermodynamic aspects of small molecules are important for rational drug designing and development. Here, the interaction of Harmane (Har), a very important bioactive indole alkaloid, with AT and GC hairpin duplex−DNAs has been reported using various biophysical tools. Detailed molecular mechanism with special emphasis on binding nature, base specificity, and thermodynamics have been elucidated via probing nucleic acids with varying base compositions. Har bound to both the DNA strands exhibited hypochromic effect in absorbance whereas bathochromic and hypochromic effects in fluorescence spectra. The binding constants estimated were in the order of 10⁵ M⁻¹ (higher for GC sequence compared with AT) with 1:1 stoichiometry. Noncooperative binding mode has been observed via intercalation in both the cases. The thermodynamic profile was obtained from temperature-dependent fluorescence experiments. Both Har–AT and Har–GC complexations were exothermic in nature associated with positive entropy and negative enthalpy changes. Salt-dependent studies revealed that the binding interaction was governed by nonpolyelectrolytic and hydrophobic interaction forces. The ligand-induced structural perturbation of the DNA structures was evident from the circular dichroism data. Molecular modelling data indicated towards the involvement of hydrophobic forces and hydrogen bonding.     

Effect of gamma-irradiation on dye-DNA binding.

The effect of gamma-rays on the binding of proflavine and acridine orange to DNA was investigated by spectrophotometry. The effect of irradiation was observed on the buffered solutions of the free dye and free DNA. A dose of about 35 krad caused a hyperchromicity of 30-40 per cent to the DNA peak at 258 nm, while the same dose introduced a hypochromic effect to the monomer peaks of the dyes by 30 per cent. This implied that gamma-rays have an effect of decreasing the monomer concentration of free-day molecules in solution. From the results, we conclude that more dye is bound to the changed conformation of dye-bound DNA on irradiation. Scratchard-binding isotherms drawn for the unirradiated and irradiated complexes of Pf-DNA showed interesting differences. Similar isotherms could not be obtained for the acridine orange-DNA system.     

Interaction of phenosafranine with nucleic acids and model polyphosphates. I. Self-aggregation and complex formation with inorganic polyphosphates

Aggregation or phenosafranine in concentrated aqueous solutions and its interaction with polyphosphates was Studied by absorption and fluorescence spectroscopy. At concentrations > 10(-3) M phenosafranine forms dimers (Kd = 3.8 x 10(2) l.mole(-1)), which are characterized by a hypsochromic shift of the visible and near ultraviolet absorption maxima accompanied by a hypochromic effect. No fluorescence could be detected from phenosafranine dimers. Analogous spectral changes were observed when a polyphosphate was titrated with phenusafranine, which indicated that with increasing saturation of the polyphosphate binding sites phenosafranine gradually became bound in the aggregated form. Full saturation of the polyphosphate binding sites with phenosafranine was reached only when an excess of free dye was present. The cooperative binding of phenosafranine to a polyphosphate could be evaluated by means of a theory proposed by Schwarz et al. At the zero ionic strength and at 25 degrees C the binding was characterized by cooperative binding constant K = 6.2 x 10(5) l.mole(-1), number of binding sites per monomeric phosphate residue g = 0.4, and cooperativity parameter q reverse similar 30. Spectroscopic properties of phenosafranine in the aggregated and poly phosphate-bound stotes were compared with those of ethidium bromide.     

Muscle pyruvate kinase: interaction with substrates and analogues studied by difference spectroscopy. Comparative studies of the substrate-binding sites of various ATP phosphotransferases.

The substrate binding sites of pyruvate kinase have been studied by means of spectrophotometric investigations. Two binding sites, one for the nucleotide substrate and one for the acceptor, have been characterized. The interaction of nucleotide substrates with the enzyme, which is metal-dependent, results in a perturbation of the spectrum of the nucleotide chromophore characterized by hypochromic and red shift effects; the hydrophobicity of the nucleotide site was estimated by using a reporter group reagent, 2-(dansylamino)ethyl monophosphate. The comparison between the binding sites of several ATP phosphotransferases is discussed and some common features are reported.     

The self-organization of adenosine 5'-triphosphate and adenosine 5'-diphosphate in aqueous solution as determined from ultraviolet hypochromic effects

The self-association of adenosine 5'-triphosphate (ATP) and of adenosine 5'-diphosphate (ADP) was studied in aqueous solution at different pH values, over the concentration range from 5 x 10(-6) to 5 x 10(-2) M, by ultraviolet spectroscopy. Measures of the molar absorptivity of the ultraviolet bands of these compounds with increasing concentration have shown two hypochromic effects, at concentrations below 10(-3) and above 10(-3) M, respectively. These results can be interpreted in terms of self-association processes involving the formation of dimers and of polymers. From the fitting of the experimental curves of hypochromic effects, self-association constants for dimerization and polymerization were calculated. The results obtained are discussed in relation to the values reported in the literature and indicate the influence of the concentration range not only on the numerical value but also on the order of magnitude of the association constants. Comparison of ATP with ADP shows that the length of the phosphate chain may be a relevant feature in the nature of the self-organization processes in these adenine nucleotides in aqueous solution.     

The Study of Menstrual and Other Blood Loss,and Consequent Iron Deficiency,by Fe59 Whole-body Counting

A recently established method of in vivo radioiron investigation in humans, employing a steel-room whole-body counter, has been applied to the study of Fe⁵⁹ absorption and loss in seven menstruating women, six with menorrhagia and hypochromic anemia. All six were found by this method to be iron-deficient, having radioiron absorptions of 53.7-97.5% (normal 5.7-24.7%). With almost 100% radioiron incorporation into the red-cell mass, subsequent drops in Fe⁵⁹ activity, when correlated with monthly menses, revealed estimated menstrual blood losses of 110-550 c.c. The single normal patient absorbed 19.6% of the tracer, with only 33-59 c.c. menstrual blood loss. Additional applications of the technique in assessing episodic (e.g., epistaxis) and continuous (e.g., gastrointestinal) blood loss are also described. The method would appear eminently applicable to the study of any hypochromic anemia of hemorrhagic origin.     

Interpretation of hypochromic and hyperchromic intensity changes in the Raman spectra of polypeptides and polynucleotides undergoing transition.

The hyperchromic and hypochromic changes in the intensity of the amide-I and amide-III lines of polypeptides and certain ring vibrations of the bases of polynucleotides are shown to be related to similar changes in the lower energy uv absorption bands. The selection rules strictly limit the pairs of excited electronic states that can contribute to the elements of the polarizability matrix. An energy-dependent term in this equation weights the contribution of the pairs of electronic transitions in favor of those involving the lower energy transitions. For both polypeptides and polynucleotides, there is a large hypochromic inensity change in the first π → π* exciton band upon the coil-to-helix transition. Through the selection rules, certain conformationally sensitive Raman lines are shown to derive their intensity predominantly from this band and hence also display hypochromism. Again, through an application of the selection rules, certain Raman lines can be demonstrated to depend predominantly for their intensity upon the n → π* transition, and consequently have the opposite hyperchromic intensity change upon the same conformational transition.     

Interaction of a novel antitumor agent TAS-103 with DNA.

Interaction of a novel antitumor agent TAS-103 with DNA has been studied by a variety of methods including thermal melting study, UV-Visible spectroscopy, 1H- and 31P-NMR spectroscopy. Thermal melting study indicated that TAS-103 stabilizes the double stranded form of DNA and the relative binding strength of TAS-103 is equal to that of ethidium bromide (EtBr). UV-Visible spectroscopy demonstrated that titration curves are nearly identical with all DNA oligomers producing a hypochromic and hypsochromic effect. A hypsochromic effect of TAS-103 is differ from typical intercalators such as EtBr and Actinomycin D that exhibit a bathochromic effect. 1H- and 31P-NMR spectroscopy revealed that TAS-103 has mainly two binding modes. Major binding mode is outside binding and minor binding mode is intercalation.     

Temperature dependence of the electronic absorption spectra of polynucleotides and their components]

The temperature dependence of UV-absorption spectra of solutions nucleic bases, nucleosides, nucleotides and metilated bases, uncapable of tautomerization has been studied. The nature of such dependence, its connection with hypochromic effect is discussed. It is shown that for some methods of investigating polynucleotides it is necessary to take into account the temperature changes spectra of monomers.     

Synthesis of Oligopeptides as Polynucleotide Analogs

Abstract

Several dipeptides which have a uracil moiety in their side chains were designed as nucleotide analogs. Oligopeptides obtained from the dipeptides as monomer units were water-soluble, but exhibited no hypochromic effect with poly A or poly dA.

     

Quantum-mechanical study of the hypochromic effect in polynucleotides. Intra- and interstrand interaction contributions.

The first uv absorption band hypochromism of poly(dA) · poly(dT), poly(dG) · poly(dC), poly(dA), poly(dT), poly(dG), and poly(dC) is calculated with the help of perturbation theory on the basis of monomer characteristics computed by the Pariser-Parr-Pople method taking into account all singly excited configurations. The theoretical results obtained are in good agreement with experimental values of hypochromism. The origin of the hypochromic effect in the double-stranded polynucleotides is investigated. It is shown that intrastrand interactions between the bases make the main contribution to hypochromism (60–76%), while the contribution of the Watson–Crick-pair formation is small (2–12%). The essential part of hypochromism (22–28%) is due to the interstrand interactions between the bases that are not coupled by hydrogen bonds. The discussion of the experimental data shows that the present theoretical investigation could serve as a basis for the correct treatment of experimental data.     

四苯基卟啉氯化锰与ctDNA的相互作用

目的:探究非水溶性的四苯基卟啉氯化锰[(TPP)MnCl]与小牛胸腺DNA(ctDNA)的相互作用方式及机理.方法:借助紫外-可见光谱、荧光光谱和电化学等手段研究了(TPP)MnCl与ctDNA相互作用的过程.结果:两者作用后,(TPP)MnCl的紫外-可见光谱在Soret带减色30%;EB-DNA体系的荧光猝灭;(TPP)MnCl的循环伏安也明显变化.实验测得(TPP)MnCl与ctDNA的表观结合常数为9.3×105L·moL-1.结论:在实验条件下,(TPP)MnCl与ctDNA以静电结合方式相互作用.     

Effects of legal termination on subsequent pregnancy.

Two hundred and eleven patients who had undergone vaginal termination and were pregnant again were investigated; 43-2% had become pregnant within one year of termination. The overall fetal loss in the 211 patients was 17-5% compared with 7-5% in a group matched for parity but consisting of patients who were pregnant after a spontaneous abortion. Altogether 4-3% of pregnancies after legal abortion ended as first trimester abortions, 8-5% as second trimester abortions, and 13-7% in premature delivery. Among 11 women whose cervices had been lacerated at the time of legal termination the fetal loss in subsequent pregnancy was 45-5%, and only one pregnancy went beyond 36 weeks. Routine Shirodkar suture may be beneficial when the cervix is known to have been damaged at legal abortion. Several patients had asked that their general practitioner should not be told of their termination, and such patients may not admit their termination during a subsequent pregnancy, which could thus be jeopardised. No evidence was found to suggest that infants of patients with a history of legal termination are small for dates.     

Multiple mechanisms for hereditary sideroblastic anemia.

Hereditary sideroblastic anemia (HSA) is a heterogeneous group of inherited anemic disorders which is characterized by the presence of ringed sideroblasts in the bone marrow, microcytic hypochromic anemia and typically its X-linked inheritance in patients. It has been shown that a deficiency of the erythroid-specific delta-aminolevulinate synthase (ALAS-E) activity is responsible for pyridoxine-responsive HSA in many patients, however, the pathogenesis of other types of HSA remains still unknown. In this article, recent evidence suggesting multiple causes for HSA is summarized and discussed.     

87 The melting of DNA in the presence of meso-tetra-pyridyl porphyrins with different peripheral substituents

The influence of water-soluble cationic 3N- and 4N-pyridyl porphyrins with different peripheral substituents (oxyethyl, buthyl, allyl, and metallyl) on melting parameters of DNA has been studied. Results indicate that the presence of porphyrin changes the shape and parameters of DNA melting curve. The increase of porphyrins concentration results in the increase of the melting temperature (Tm) and the melting interval (ΔT) of DNA. At the porphyrin-DNA concentration ratio r?=?0.01, changes in the melting temperature have not been observed. The melting intervals almost do not change upon adding of the 4N-porphyrins, while the decrease of ΔT, in the presence of 3N-porphyrins, is observed. Because the intercalation binding mechanism occurs in GC-rich regions of DNA, we assume that 3N-porphyrins, intercalated in GC-rich regions, reduce the thermal stability of these sites, bringing them closer to the thermal stability of the AT-sites, which is the reason for the decrease in the melting interval. While at the relative concentration r?=?0.01 for 4-N porphyrins, already the external binding mechanism “turns on” and the destabilizing effect of porphyrins on GC-pairs compensates stabilizing effect on AT-pairs, as a result of which change in the melting of DNA upon complexation with these porphyrins is not observed. The decrease of the hypochromic effect also indicates the intercalation of investigated porphyrins in the DNA structure, which weakens the staking interaction of base pairs of DNA. The increase of the hypochromic effect of DNA upon binding with porphyrin depends on the type of peripheral substituents of the porphyrin. The results show that porphyrins with butyl and allyl substituents weaken staking interaction of base pairs less than porphyrins with other substituents. The largest change was observed for metallyl porphyrins. It can be the result of bulky peripheral substituents, which make significant local changes in DNA structure.