Synthetic CD4 exocyclic peptides antagonize CD4 holoreceptor binding and T cell activation

We have developed peptide analogs to analyze precise human CD4 substructures involved in MHC class II binding. Forms of the complementarity determining-like regions (CDRs) of the D1 domain of human CD4 were reproduced as synthetic aromatically modified exocyclic (AME) analogs and tested for their ability to block CD4-MHC II interactions and T cell activation. The exocyclic derived from CDR3 (residues 82-89) of human CD4, which specifically associated with CD4 on the T cell surface to create a heteromeric CD4 complex, blocked IL-2 production and antagonized the normal function of the CD4 receptor. The approach of creating novel synthetic antagonistic receptor complexes may represent a new receptor specific pharmaceutical approach to modulate biological function.     

Performance analysis of 2-D inverse fast cosine transform employingmultiprocessors

The modeling and performance analysis of the two-dimensional (2-D) inverse fast cosine transform (FCT) algorithm on a multiprocessor has been considered. The computational and communication complexities of this algorithm on a shared bus, multistage interconnection network, and on mesh-connected multiprocessor architectures have been determined. The performance of the three multiprocessor architectures has been compared in terms of speedup, efficiency, and cost effectiveness. The evaluation shows that for this application, the indirect binary n-cube MIN connected multiprocessor architecture is the best in terms of speedup and efficiency among all three architectures considered     

Study on body mass index, lipid profile and lipid peroxidation status in coronary artery disease

Among the many known risk factors of coronary artery disease (CAD) obesity and hypercholesterolaemia are important ones. Whatever may be the risk factor, the basic pathology of CAD is deposition of altered lipids on the endothelium. One of such altered lipid is oxidatively modified low density lipoprotein (LDL). Lipid peroxidation has been assessed by several methods. Quantitation of malondialdehyde (MDA) by thiobarbituric acid (TBA) method is one of the commonly utilised method in several laboratories. In this study 40 cases of CAD were selected for evaluation. The body mass index (BMI), lipid profile and the level of lipid peroxidation (MDA) were measured. Seventeen cases (42.5%) had normal BMI (20-25), 20 cases (50%) were in the overweight range of BMI (26-30) and only 3 cases (7.5%) were in the obese group with a BMI more than 30. BMI correlated better with the level of total cholesterol (Tc), low density lipoprotein cholesterol (HDLc) and MDA. BMI did not show any correlation with triglyceride (Tg) or high density lipoprotein cholesterol (HDLc). MDA level correlated better with Tc, Tg levels and BMI, poorly correlated with LDLc and in inverse relationship was observed with HDLc.     

The oxidation resistance of MoSi2 composites

Recent work at the Naval Air Development Center demonstrates that the oxidation resistance of MoSi₂ is not significantly reduced by XD? compositing. The MoSi₂ + SiC material exhibited an oxidation resistance equal to or better than that of base MoSi₂. This excellent oxidation resistance, in conjunction with the enhanced high-temperature strength provided by XD particles, makes these materials highly attractive for use as future gas turbine engine materials. The problem of low room-temperature ductility and fracture toughness will be approached by incorporating other types of reinforcement phases.     

A note on selecting a low-order system by Davison's model simplification technique

A criterion is presented in this correspondence to select the low-order system after simplifying the given high-order system by Davison's model simplification technique. The criterion is judged by a numerical example.     

On convergence properties of eigenvalues of space discretized wave equations

A theorem along with proof for the convergence of eigenvalues of spatially discretized wave equations is established in this correspondence by extending earlier work of Mahapatra[3].     

Solid-phase synthesis of peptide nucleic acid (PNA) monomers and their oligomerization using disulphide anchoring linkers

A new simple solid-phase method has been developed for synthesizing Boc-protected peptide nucleic acid (PNA) monomers. An immobilized backbone 3 was built on Expansin resin using an ester disulphide handle: 2-hydroxypropyl-dithio-2'-isobutyric acid (HPDI). The base acetic acids of thymine 5, Z-cytosine 9, Z-adenine 12, and 6-O-benzyl guanine 17 were prepared and coupled to the immobilized backbone. The HPDI handle was cleaved under mild conditions by cyanolysis or assisted hydrolysis with tris(2-carboxyethyl)phosphine (TCEP) to give undamaged PNA monomers. These monomers were coupled to form oligomers by solid-phase method with another disulphide linkage: aminoethyldithio-2-isobutyric acid (AEDI) grafted on an amino-functionalized TentaGel resin, using in situ neutralization and TBTU as activating reagent. Final cleavage of the AEDI linker gave PNA bearing a cysteamide residue that could be useful for optimizing PNA properties. Oligomers of up to 16 residues long were assembled.     

Solitary giant skull base schwannomas--report of four cases

BACKGROUND: Solitary intracranial schwannomas not related to major nerves or neurofibromatosis as well as paranasal schwannomas are rare. Schwannomas simultaneously involving the paranasal sinuses and intracranial cavity are even rarer. METHODS: We report four cases of schwannomas simultaneously involving the intracranial cavity and paranasal sinuses. They were successfully managed by surgery. The literature on such tumors is reviewed. RESULTS: All patients were young adults; the male to female ratio was 1:3. In two patients, the tumor was predominantly intracranial with extension into the sphenoid and ethmoid sinuses, whereas in the other patients, the tumor was located predominantly in the paranasal sinuses and nasopharynx with intracranial extension. Radiologically, bone destruction was seen in three cases. The tumors were totally removed piecemeal with repair of the basal dura. Histopathologic examination confirmed the diagnosis of schwannoma in all four cases. Three patients are alive and well; one of them was reoperated for a recurrence. CONCLUSIONS: These tumors should be excised completely if possible. Radiologically, bone erosion or destruction are suggestive of malignancy but histopathology clinches the diagnosis. Therefore, drastic surgery should be avoided in these cases. Surgery is generally curative in these massive schwannomas.     

Polymetallic complexes. part iii. schiff base complexes of cobalt(ii), copper(ii), cadmium(ii) and mercury(ii)

Eight polymetallic complexes have been synthesised of the composition M₂L₂._nB [M = Co(II), n = 4, B=H₂O, M = Cu(II), Cd(II) and Hg(II), n = 0] M₂L_2'.nB [M = Co(II), n = 4, B = H₂O; M = Cu(II), Cd(II) and Hg(II), n = 0], LH₂ = bi-bidentate Schiff base derived from benzoin with m-phenylenediamine; L'Hz = tridentate Schiff base derived from benzoin with o-aminophenol. Elemental analysis, conductance, magnetic susceptibility, i.r. and electronic spectral measurements have been done to characterise the complex compounds. A dinuclear octahedral configuration has been assigned to the cobalt(II) complexes and a dinuclear square planar structure to the copper(II) complexes. A tetrahedral configuration has been attributed to the cadmiurn(II) and mercury(II) complexes.