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Biomedical subjects

S M Conrad

Publications and source records attributed to S M Conrad.

8 recordsLinked to original sources
PubMed1999

Patients' perception of recovery after third molar surgery.

PURPOSE: This study evaluated patients' perceptions of recovery after third molar surgery. METHODS: Two hundred forty-nine patients (age 13 to 37 years) at 2 clinical centers were enrolled in a prospective study before the surgical removal of third molars. Each patient was given a 21-item Health-Related Quality of Life instrument (HRQOL) to be completed each postoperative day (POD) for 14 days. The instrument was designed to assess patients' perception of recovery: pain, oral function, general activity measures, and other symptoms. Pain dimensions were recorded with a 7-point Likert-type scale; all other conditions were measured on 5-point Likert-type scales. The impact of each predictor variable such as age, gender, and length of surgery on recovery was assessed with Cochran-Mantel-Haenszel statistics, controlling for clinical center. RESULTS: After the 14-day postoperative period, 201 of the original 249 patients returned the completed HRQOL instrument; the 48 patients who did not return their diary had third molar conditions and surgery similar to the 201 patients who responded. On POD 1, 63.5% of patients reported their worst pain as severe (score, 5 to 7/7) at some time during the day. By POD 7, only 15% of patients reported their worst pain as severe. Average pain levels were much less; 29% reported their average pain as severe (score, 5 to 7/7) on POD 1, decreasing to 5.5% by POD 7. Patients experienced substantial interference in oral function; chewing, 85%; mouth opening 78.5%, and speaking 37.5% on POD 1. By POD 6, oral function had improved; chewing, 19%, mouth opening, 15%; and speaking, 1.5%. General measures also were affected on POD 1; social activity, 61.5%; recreation, 70.5%; and daily routine, 60%. Patients assumed a more normal lifestyle by POD 5. Swelling seemed to be at its maximum on PODs 1 and 2 (day 1, 53%; day 2, 61%) and decreased markedly by POD 5 (10%). Food collection in the surgical sites posed the biggest problem for patients on POD 9 (20%). Age was not a predictor of prolonged recovery. However, surgery time 30 minutes or longer, or having all third molars below the occlusal plane, did prolong recovery. Females also reported a longer recovery period. CONCLUSIONS: This information is valuable to patients deciding on third molar surgery and to clinicians providing informed consent.

Adolescent↗
PubMed1987

Inhibition of beta-crystallin cross-linking in the Ca2+-treated lens.

beta-Crystallin dimers of approximately 55,000 weight are among the early products of protein cross-linking in Ca2+-treated rabbit lens, caused by the activation of intrinsic transglutaminase; formation of the cross-linked species can be blocked by 75 mM histamine (Lorand et al, Biochemistry, 24:1525-1531, 1985). As an extension of this work, we initiated a search for more specific inhibitors of cross-linking in this system. Of the compounds tested so far, hydroxylamine, methoxyamine, bisaminoxypropane and aminoacetonitrile were particularly effective, inhibiting the generation of the cross-linked dimer in the 5 to 10 mM concentration range during a 4 hr treatment of the lens with Ca2+-ions.

Animals↗
PubMed1985

Formation of a 55 000-weight cross-linked beta crystallin dimer in the Ca2+-treated lens. A model for cataract.

Incubation of lens in Ca2+-containing media, considered by several investigators to be a useful model of cataract formation, gave rise to significant alterations in the covalent structures of various proteins. In rabbit lens, when sodium dodecyl sulfate-polyacrylamide gel electrophoresis was used after reduction of disulfides in urea, the most readily observable changes were (i) disappearance of 210K, 95K, and 60K proteins, (ii) modifications of alpha crystallin subunits, (iii) alterations of beta H crystallins, and (iv) de novo production of 55K and higher molecular weight polymers. The addition of leupeptin inhibited the disappearances of 210K, 95K, and 60K proteins and the alteration of alpha crystallins, suggesting that all these were caused by a Ca2+-activated protease. The proteolytically sensitive 60K species was identified as vimentin, a component of intermediate filaments. Formation of the 55K material and of higher molecular weight polymers during Ca2+ treatment of the lens could be prevented by histamine, a compound known to inhibit the transglutaminase-mediated cross-linking of proteins by epsilon-(gamma-glutamyl)lysine peptide bonds in other biological systems. It could also be shown by immunoblotting that an antibody raised against the 55K material reacted selectively with beta crystallins of normal lens. This indicates that the 55K product is in all likelihood an essential intermediate toward higher polymers and that the 55K product is a cross-linked dimer of certain polypeptides of beta crystallin.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Transglutaminases.

This paper is intended as a background to the topic of transglutaminases, while focusing on current ideas regarding the biological roles of these enzymes. Specifically, the following topics are discussed: geometry of forming gamma-glutamyl-epsilon-lysine cross-linked structures; energetic considerations; the gamma-glutamyl-epsilon-lysine cross-link; amine incorporation assays; artefactual incorporation of amines in cells and tissue homogenates; synthetic substrate systems; regulation of transglutaminase activities; strategies for probing transglutaminase-mediated events in biological systems; the blood clotting paradigm; transglutaminase and cell aging: the Ca2+-enriched human erythrocyte; transglutaminase and cell activation: the thrombin-stimulated human platelet and the fertilized sea urchin egg.

Acyltransferases↗
PubMed1982

Comparative studies on aldose reductase from bovine, rat and human lens.

A purification scheme for aldose reductase (alditol: NADP+ 1-oxidoreductase, EC 1.1.1.21) developed using bovine lens tissue including an affinity chromatographic step is presented which is particularly suited for small quantities of lenses. Using the affinity chromatographic method as a key step also makes it possible to obtain preparations of rat lens aldose reductase which are homogeneous. The behavior of crude preparations of aldose reductase from human lens on both ion-exchange and affinity chromatography was similar to the chromatographic behavior of the enzyme from rat and bovine lens. Comparative studies of aldose reductase obtained from the lenses of the three species demonstrate the similarity of the enzymes. These comparisons were based on molecular weights, isoelectric points, chromatographic behavior and kinetic data. Homotropic cooperativity for both NADPH and glyceraldehyde, as evidenced by a downward curvature in the Lineweaver-Burk double-reciprocal plots, had been demonstrated for aldose reductase obtained from bovine lens (Sheaff, C.M. and Doughty, C.C. (1976) J. Biol. Chem. 251, 2696-2702). Similarly, cooperativity was observed with the enzyme from both rat and human lenses and the apparent Km values at both high and low concentrations of substrate are comparable for the lens aldose reductases from all three species for both substrates.

Aldehyde Reductase↗
PubMed1982

A reaction mechanism for aldose reductase from lens.

Sheys and Doughty, (Sheys, G.H. and Doughty, C.C. (1979) Biochim. Biophys. Acta 242, 523-531) suggested a model for Rhodotorula (yeast) aldose reductase (alditol:NADP+ 1-oxidoreductase, EC 1.1.1.21) which offered a unified explanation for changes in reversibility, reaction mechanism, and effects of multivalent anions as well as substrate activation. The present paper extends this model to lens aldose reductase, explaining its similarities to the reverse reaction in Rhodotorula in regard to its reaction mechanism, as well as multivalent anion effects of sulfate, pyrophosphate and NADPH (above 20 micro M) and also substrate activation with glyceraldehyde involving formation of an abortive complex (above 50 micro M). Activation of lens aldose reductase resulted with multivalent anions, due to increased V max and apparent Km values with increasing concentration of multivalent anions. The lens enzyme mechanism is similar to the reverse reaction mechanism for the Rhodotorula enzyme, being partially random in character, based on NADP+ inhibitor studies presented here. The binding of NADPH appears to occur at a basic center containing arginine and possibly histidine. Evidence of the participation of these residues at the active center is based on time-course inactivation protection studies using reagents specific for these residues.

Aldehyde Reductase↗
PubMedDate not supplied

Confirmation of identities of propylene and ethylene glycols in anchovies by tandem mass spectrometry.

A gas chromatographic/tandem mass spectrometric (GC/MS/MS) method has been developed for confirming the identity of propylene and ethylene glycols added to bait fish for preservation. Bait fish are occasionally illegally diverted to human food use. The bait fish were extracted with methanol, the extract was centrifuged and filtered, and the filtrate was concentrated 10-fold and then analyzed by GC/MS/MS. The glycols were separated chromatographically without derivatization or preliminary cleanup. Isobutane positive ion chemical ionization was used to generate the protonated molecular ion species of each glycol. Product-ion MS/MS experiments were performed to obtain spectra to confirm the identities of propylene and ethylene glycols. The identities of these 2 compounds in anchovy extracts were successfully confirmed by this approach.

Animals↗