Effects of honey consumption on enamel microhardness in normal versus xerostomic patients

BACKGROUND: This report describes the pathology of a myolipoma which occurred in the eyelid. Myolipoma is a benign hamartomatous tumour in which smooth muscle cells are interspersed with adipocytes. PATIENT DETAILS: An irregular yellowish tumour (30 x 25 mm) with illdefined borders had been present for 50 years in the medial part of the left lower eyelid of a 67-year-old woman. The tumour was excised and studied by conventional histology, immunohistochemistry and transmission electron microscopy. RESULTS: The tumour was formed by bundles of spindle-shaped cells with cigarshaped nuclei intermingled with multiloculated clear cells containing small eccentric nuclei. By immunohistochemistry, positive staining of the spindle cells was restricted to smooth muscle actin and desmin; the clear cells were non-reactive with the immunohistochemical panel, but fat was identified within the cytoplasm. The ultrastructural features of the spindle cells were those of a leiomyoma, while the clear cells were classified as adipocytes. CONCLUSION: This tumour was considered to originate from the media of blood vessels within the tumour.     

The mae1 gene of Schizosaccharomyces pombe encodes a permease for malate and other C4 dicarboxylic acids

The mae1 gene of the yeast Schizosaccharomyces pombe was identified on the basis of its ability to complement a mutant defective in the transport of malic acid. Analysis of the DNA sequence revealed an open reading frame of 1314 base pairs, encoding a polypeptide of 438 amino acids with a predicted molecular weight of 49 kDa. A hydropathy profile of the predicted amino acid sequence revealed a protein with ten membrane-spanning or associated domains and hydrophilic N- and C- termini. The predicted secondary structure of the protein is similar to models proposed for other integral mambrane proteins from both prokaryotes and eukaryotes. The S. pombe mae1 gene encodes a single mRNA of 1·5 kb. The mae1 gene is expressed constitutively and is not subject to catabolite repression as was previously reported for the malate permease systems of Candida utilis and Hansenula anomala. The mae1 gene was mapped 2842 bp 5′ to the MFm1 gene on chromosome I. Transport assays revealed that the mae1 gene encodes a permease involved in the uptake of L-malate, succinate and malonic acid. The sequence of the S. pombe mae1 gene is available in GenBank under Accession Number U21002.     

An efficient parallel implementation of the Monte Carlo particle simulation algorithm on a network of personal computers

MC‐PVM, an efficient parallel implementation of the Monte Carlo device simulation on a network of personal computers, is presented. A more efficient leap‐frog derivative of the MC‐PVM algorithm is also discussed. The network of personal computers has been employed into a parallel virtual machine (PVM). To demonstrate the viability of employing a network of personal computers for the parallel implementation of the MC simulation, 60 MHz Pentium computers were utilized. The accuracy and efficiency of the proposed parallel algorithms have been investigated by applying it to a simulation of a millimeter‐wave Gunn‐effect relaxation oscillator. Finally, a few conclusions will be drawn about the work presented here. Copyright © 2000 John Wiley & Sons, Ltd.     

Stability, activity and flexibility in {alpha}-lactalbumin

-Lactalbumins and the type-c lysozymes are homologues with similarfolds that differ in function and stability. To determine ifthe lower stability of -lactalbumin results from specific substitutionsrequired for its adaptation to a new function, the effects oflysozyme-based and other substitutions on thermal stabilitywere determined. Unblocking the upper cleft in -lactalbuminby replacing Tyr103 with Ala, perturbs stability and structurebut Pro, which also generates an open cleft, is compatible withnormal structure and activity. These effects appear to reflectalternative enthalpic and entropic forms of structural stabilizationby Tyr and Pro. Of 23 mutations, only three, which involve substitutionsfor residues in flexible substructures adjacent to the functionalsite, increase stability. Two are lysozyme-based substitutionsfor Leu110, a component of a region with alternative helix andloop conformations, and one is Asn for Lys114, a residue whosemicroenvironment changes when -lactalbumin interacts with itstarget enzyme. While all substitutions for Leu110 perturb activity,a Lys114 to Asn mutation increases T_m by more than 10°Cand reduces activity, but two other destabilizing substitutionsdo not affect activity. It is proposed that increased stabilityand reduced activity in Lys114Asn result from reduced flexibilityin the functional site of -lactalbumin.     

CITYWORK: Application of Collaborative Technologies for Infrastructure Management

This paper describes a collaborative maintenance management application called CITYWORK being developed for the Public Works Department at the Fort Gordon Army Installation in Augusta, Ga. The work described in this paper is being carried out in the context of project “CITY” (Civil Infostructure TechnologY—National Science Foundation Grant No. ECS94-22730) to support the sustainable management of civil infrastructure. Infrastructure management requires the coordination of a variety of efforts and integration of information across a range of facilities. CITYWORK addresses coordination, collaboration, and integration in the maintenance management process in a context of sound organizational behavior. The project involves an interdisciplinary team including engineers and social scientists from the IMPACT laboratory at the University of Southern California, Los Angeles, University of Illinois at Urbana-Champaign, and U.S. Army Construction Engineering Research Laboratories, Champaign, Ill. CITYWORK supports the maintenance workflow process by providing private, persistent workspaces for each participant to work on the specific aspects of their interests (e.g., estimators work on generating cost estimates) and share the work with others in an asynchronous manner.     

Discovery of MK‐8970: An Acetal Carbonate Prodrug of Raltegravir with Enhanced Colonic Absorption

Developing new antiretroviral therapies for HIV‐1 infection with potential for less frequent dosing represents an important goal within drug discovery. Herein, we present the discovery of ethyl (1‐((4‐((4‐fluorobenzyl)carbamoyl)‐1‐methyl‐2‐(2‐(5‐methyl‐ 1,3,4‐oxadiazole‐2‐carboxamido)propan‐2‐yl)‐6‐oxo‐1,6‐dihydropyrimidin‐5‐yl)oxy)ethyl) carbonate (MK‐8970), a highly optimized prodrug of raltegravir (Isentress). Raltegravir is a small molecule HIV integrase strand‐transfer inhibitor approved for the treatment of HIV infection with twice‐daily administration. Two classes of prodrugs were designed to have enhanced colonic absorption, and derivatives were evaluated in pharmacokinetic studies, both in vitro and in vivo in different species, ultimately leading to the identification of MK‐8970 as a suitable candidate for development as an HIV therapeutic with the potential to require less frequent administration while maintaining the favorable efficacy, tolerability, and minimal drug–drug interaction profile of raltegravir.     

C2 domain conformational changes in phospholipase C-delta 1

The structure of the PH-domain truncated core of rat phosphoinositide-specific phospholipase C-delta 1 has been determined at 2.4 A resolution and compared to the structure previously determined in a different crystal form. The stereochemical relationship between the EF, catalytic, and C2 domains is essentially identical. The Ca2+ analogue Sm3+ binds at two sites between the jaws of the C2 domain. Sm3+ binding ejects three lysine residues which bridge the gap between the jaws and occupy the Ca2+ site in the apoenzyme, triggering a conformational change in the jaws. The distal sections of the C2 jaws move apart, opening the mouth by 9 A and creating a gap large enough to bind a phospholipid headgroup.     

In situ computerized optical reflectivity measurement system forion implantation

A computerized in situ optical reflectivity measurement system for the quantitative determination of material parameter changes of a substrate during the process of ion implantation is presented. These changes are related to the extent and nature of the induced crystal disorder in the substrate. The system consists of an optical reflectometer, with data acquisition and signal processing capabilities. For each sample a case history of the implant is obtained in the form of a continuous graph of reflectivity vs. a desired implantation parameter (e.g. dose). Examples regarding the implantation of ³¹P⁺ , ⁴⁰Ar⁺, and ¹⁴N⁺ are presented. Additional suggestions for further system development and applications are made. Among the advantages of in situ measurements are the time-effort-expense. savings, a higher yield of experimental data per sample, higher accuracy, repeatability, and various possibilities of process control