Sithembiso Mntambo Nkosi: Organic Intellectual

Thirty-four different loci for hereditary spastic paraplegias have been mapped, and 16 responsible genes have been identified. Autosomal recessive forms of spastic paraplegias usually have clinically complex phenotypes but the SPG5, SPG24 and SPG28 loci are considered to be associated with 'pure' forms of the disease. Very recently, five mutations in the CYP7B1 gene, encoding a cytochrome P450 oxysterol 7-alpha hydroxylase and expressed in brain and liver, have been found in SPG5 families. We analysed the coding region and exon-intron boundaries of the CYP7B1 gene by direct sequencing in a series of 82 unrelated autosomal recessive hereditary spastic paraplegia index patients, manifesting either a pure (n = 52) or a complex form (n = 30) of the disease, and in 90 unrelated index patients with sporadic pure hereditary spastic paraplegia. We identified eight, including six novel, mutations in CYP7B1 segregating in nine families. Three of these mutations were nonsense (p.R63X, p.R112X, p.Y275X) and five were missense mutations (p.T297A, p.R417H, p.R417C, p.F470I, p.R486C), the last four clustering in exon 6 at the C-terminal end of the protein. Residue R417 appeared as a mutational hot-spot. The mean age at onset in 16 patients was 16.4 +/- 12.1 years (range 4-47 years). After a mean disease duration of 28.3 +/- 13.4 years (10-58), spasticity and functional handicap were moderate to severe in all cases. Interestingly, hereditary spastic paraplegia was pure in seven SPG5 families but complex in two. In addition, white matter hyperintensities were observed on brain magnetic resonance imaging in three patients issued from two of the seven pure families. Lastly, the index case of one family had a chronic autoimmune hepatitis while his eldest brother died from cirrhosis and liver failure. Whether this association is fortuitous remains unsolved, however. The frequency of CYP7B1 mutations were 7.3% (n = 6/82) in our series of autosomal recessive hereditary spastic paraplegia families and 3.3% (n = 3/90) in our series of sporadic pure spastic paraplegia. The recent identification of CYP7B1 as the gene responsible for SPG5 highlights a novel molecular mechanism involved in hereditary spastic paraplegia determinism.

Carbon Nanotubes (CNTs) have exceptionally high strength and high elastic modulus, as well as good electrical and thermal conductivity. The objective of current research is to develop new lightweight, strong, and conductive materials by using CNTs primarily in pure form. Recently, we have developed a solid-state processing method that enables the CNTs to be assembled into pure yarns and webs, avoiding the problems associated with the presence of a binder, and improving the exploitation of the inherent properties of the individual CNTs. In this paper will report on recent experience with spinning CNT yarns and the effect of twist on selected properties. We also report our results on knitted tubes, in both pure and composite form.

Carbon dioxide is abundant in ice mantles of dust grains; some is found in the pure crystalline form as inferred from the double peak splitting of the bending profile at about 650 cm$^{-1}$. To study how CO$_2$ segregates into the pure form from water-rich mixtures of ice mantles and how it then crystallizes, we used Reflection Absorption InfraRed Spectroscopy (RAIRS) to study the structural change of pure CO$_2$ ice as a function of both ice thickness and temperature. We found that the $\nu_1+\nu_3$ combination mode absorption profile at 3708~cm$^{-1}$ provides an excellent probe to quantify the degree of crystallinity in CO$_2$ ice. We also found that between 20 and 30~K, there is an ordering transition that we attribute to reorientation of CO$_2$ molecules, while the diffusion of CO$_2$ becomes significant at much higher temperatures. In the formation of pure crystalline CO$_2$ in ISM ices, the rate limiting process is the diffusion/segregation of CO$_2$ molecules in the ice instead of the phase transition from amorphous to crystalline after clusters/islands of CO$_2$ are formed.

Spectrophotometric and spectrofluorimetric methods for the determination of ramipril in its pure and dosage form

Hydrochlorothiazide (HCZ) and Amiloride hydrochloride (AMH) are generally co-formulated in antihypertensive formulations. Different analytical methods have been developed for their simultaneous determination in their binary mixtures but none of them analyzed both drugs in the presence of related impurities of HCZ; Salamide (DSA) and Chlorothiazide (CTZ). Accordingly; a simple, sensitive and highly selective RP-HPLC method was developed for their simultaneous determination in pure form and pharmaceutical formulations. Chromatographic separation was carried out within 10 min using an ODS-C18 column (250×4.6 mm, 5 µm) using 0.05 MKH2PO4 : acetonitrile: triethylamine (90: 10: 0.3 by volume, pH 3.6) as mobile phase, flow rate 1.5 mL min−1 with UV detection at 260 nm.Calibration curves were builtin the range of 1-50, 1-20, 1-12 and 1-20 µg mL-1 for HCZ, AMH, DSA and CTZ, respectively. HCZ and AMH were successfully analyzed in their pure and pharmaceutical form. The results obtained were statistically compared to those obtained by the reported method with no significant difference, therefore the proposed method can be applied in routine quality control analysis of the drug products.

X-linked hereditary spastic paraplegias (HSPs) present with two distinct phenotypes: pure and complicated. The pure form is characterized by slowly progressive weakness and spasticity of the lower limbs, whereas the complicated forms have additional features (optic neuropathy, retinopathy, extrapyramidal disturbance, dementia, epilepsy, ataxia, ichthyosis, mental retardation, and deafness). Three X-linked loci have been identified for the complicated HSP, while mutations in the proteolipid gene (PLP) (locus SPG2) were implicated in both pure and complicated forms. The absence of identified mutations in the PLP gene in families with both complicated and pure HSP, linked to the SPG2 locus, suggests the existence of another gene in close proximity. We had previously reported a large pedigree with an X-linked form of pure HSP affecting 24 males [Zatz et al., 1976: J Med Genet 13:217-222]. Here, we present the results of linkage analysis in 19 members of this Brazilian family with markers in or near the PLP locus. Positive LOD scores were obtained with markers at the PLP locus (Zmax = 2.41 at Theta = 0); however, no mutation was found in the coding region of PLP, the intron-exon boundaries, or part of the promoter region. The possibility of a duplication of the PLP gene was also excluded. These results suggest either that there is another X-linked gene in close proximity to the PLP gene or that a novel mutation in the noncoding regions of the PLP gene may cause the disease in this family.

Spectrophotometric method for the determination of amlodipine besylate in pure and dosage forms using 7,7,8,8-tetracyanoquinodimethane and tetracyanoethylene

Utility of oxidation–reduction reaction for the determination of ranitidine hydrochloride in pure form, in dosage forms and in the presence of its oxidative degradates

WHITEHEAD'S TRANSFORMATION OF PURE ACT IN AN EFFORT to avoid any final bifurcation into two realms of being and becoming, as in Plato, Aristotle argued that only concrete particulars were fully actual, with forms only derivatively existent as the forms of these actualities. Yet under pressure from his understanding of the basic contrast between matter and form in terms of potentiality and actuality, Aristotle was driven more and more to identify form and actuality .1 Thus the immaterial reality of God becomes a pure, unchanging actuality not readily distinguishable from Plato's form of the Good, although Aristotle seeks to endow it with an interior life of ceaseless activity of "thinking." As pure actuality God is thus conceived as pure form, without matter. How pure form can engage in ceaseless activity of any sort is not clearly explained. Thomas Aquinas was able to explain the activity of immaterial being primarily by freeing the basic polarity of potentiality and actuality from its exclusive identification with matter and form. It was also possible to apply this contrast to form and esse or the act of being. Purely immaterial forms, such as angelic intelligences, could not create themselves by their own power, but were dependent upon the creative act of God whereby they received their own act of being. Thus pure form was in potency to this act of being. As infinite esse, God was pure actuality without any admixture of potentiality, and by the same token he was pure activity in no wise limited by any element of form.2 1 Here see Ivor Leclerc, " Form and Actuality," pp. 169-89 in the book he edited, The Rdevance of Whitehead (London: George Allen &Unwin, 1961). Pages 169-71 summarize this problem for Aristotle; the rest of the essay shows how Whitehead successfully maintains the distinction between form and actuality. • The nature of the act of being is ably explained by Etienne Gilson in his Being and Some Phuosophm-s (Toronto: Pontifical Institute of Medieval Studies, 381 382 LEWIS S. FORD This solution was not without its difficulties. God's relation to form is not clarified thereby. We have the formula, that his essence is his existence, i.e. his infinite esse, but this seems to have the force of making him sheer existence devoid of any essence whatever, since any element of form would in him represent a potentiality not fully enacted. Then God becomes radically unknowable, except insofar as it is possible to know him without the mediation of form. The most acute difficulty, however, emerges from religious concerns. The perfection of God is expressed as pure act, but pure act appears to be devoid of all receptivity. Receptivity is understood in terms of passive potentiality, which pure act emphatically excludes. Besides, divine perfection must be unchanging, for that which is already perfect can only change for the worse. Yet receptivity to the world and to our sorrows and achievements is undeniably part of divine perfection, as Charles Hartshorne has eloquently shown us years ago.8 He speaks for a widespread contemporary sensitivity, a sensitivity implicitly acknowledged hy ingenious attempts to affirm such personal receptivity while at the same time preserving the classical immutability of God.4 In addition, if none of our achievements are received into the divine life and have an effect upon his, they seem lacking in any ultimate significance . Though in itself pure self-giving activity, the Thomistic God of pure act, because utterly devoid of all receptivity, strikes many of our contemporaries just as static and unyielding as the unity of pure form. Thomas succeeded in transforming pure act from pure form to pure activity. We must now complete the transformation by reconceiving this activity in a way so as to include receptivity. 195~), chapter five, and The Christian Philosophy of St. Thomas Aquinas (New York: Random House, 1956), chapter one. •The Divine Relativity (New Haven: Yale Univerity Press, 1948). •See particularly W. Norris Clarke, S. J. "A New Look at the Immutability of God," in God Knowable and Unknowable, ed. Robert J. Roth, S. J. (New York: Fordham University Press, 1978) , and my response, " The Immutable God and Father Clarke " in The New Scholasticism, 49...

BackgroundEtodolac (ETD) is a non-steroidal anti-inflamatory antirheumatic drug. A survey of the literature reveals that there is no method available for the determination of ETD in pure form and pharmaceutical formulations by oxidation-reduction reactions.ResultsWe describe three simple, sensitive and reproducible spectrophotometric assays (A-C) for the determination of etodolac in pure form and in pharmaceutical formulations. Methods A and B are based on the oxidation of etodolac by Fe3+ in the presence of o-phenanthroline (o-phen) or bipyridyl (bipy). The formation of the tris-complex on reaction with Fe3+-o-phen and/or Fe3+-bipy mixtures in acetate buffer solution at optimum pH was demonstrated at 510 and 520 nm with o-phen and bipy. Method C is based on the oxidation of etodolac by Fe3+ in acidic medium, and the subsequent interaction of iron(II) with ferricyanide to form Prussian blue, with the product exhibiting an absorption maximum at 726 nm. The concentration ranges are 0.5–8, 1.0–10 and 2–18 μg mL-1 respectively for methods A, B and C. For more accurate analysis, Ringbom optimum concentration ranges were calculated, in addition to molar absorptivity, Sandell sensitivity, detection and quantification limits.ConclusionOur methods were successfully applied to the determination of etodolac in bulk and pharmaceutical formulations without any interference from common excipients. The relative standard deviations were ≤ 0.76 %, with recoveries of 99.87 % – 100.21 %.

Delocalization and charge transfer studies of PERMENDUR49, KOVAR and Ti50Co50 alloys from relative K X-ray intensity ratios

Development of novel univariate and multivariate validated chemometric methods for the analysis of dasatinib, sorafenib, and vandetanib in pure form, dosage forms and biological fluids

Of 23 children with hereditary spastic paraplegia (HSP), spasticity was the only neurological abnormality in eight patients (pure form). Additional neurological abnormalities in the 15 with complicated HSP included cognitive impairment, pseudo-bulbar palsy, cerebellar dysfunction and polyneuropathy. 19 children presented with abnormal gait, recognised at a mean age of three years in the pure form and five years in the complicated form. These forms were distinguished at a mean age of 11 years. Early non-motor developmental delay or rapidly ascending paraparesis, with spread of spasticity to the arms and with involvement of bulbar structures, predicted development of the complicated form. The pure form was inherited in an autosomal dominant manner in five patients. The autosomal recessive form was commonly associated with additional neurological abnormalities and a more rapid rate of progression.

A simple, sensitive and accurate spectrophotometric method of determination of Sulfacetamide (SAC) in pure form and pharmaceutical formulation.The method is based on the formation of (SAC) complex. The reaction between of the Sulfacetamide with the mixture of metol and potassium hexacyanoferrate (ΙΙΙ) was evaluated for the spectrophotometric determination of the Sulfacetamide. The maximum absorbance of the colored complex occurred at λ=540nm. Reaction conditions have been optimized to obtain (SAC) complex of high sensitivity and longer stability. Under optimum conditions the absorbance of the (SAC) complex where found to increase linearly with increase in concentration of the Sulfacetamide, which corroborated with correlation coefficient value. The concentration ranges are 0.1-100 μg ml-1 with detection limit 0.01842μg ml-1 and relative standard deviation 0.74 % and relative error of prediction for drug were lower.The proposed method was successfully applied to determine of the selected Sulfacetamide in pure form and pharmaceutical formulations with good precisionand accuracy compared to standard method as revealed by t- and F- values and the results obtained agree well with the labeled contents.

Simple mathematical data processing method for the determination of sever overlapped spectra of linagliptin and empagliflozin in their pure forms and pharmaceutical formulation: Fourier self deconvulated method