[Current aspects of facelift surgery]. / Aktuelle Aspekte der Facelift-Chirurgie.

In the care of the aging face, the facelift procedure occupies the center of attention. Of the many techniques available, only a few procedures fulfill the justifiable expectations that both patient and physician should have of such an intervention to reach the four goals of a facelift operation: create a natural, nonoperated appearance, obtain long-term durability, ensure a minimal complication rate, and restore or maintain a youthful vibrancy. This can especially be achieved with the so-called super-extended face lift with SMAS dissection, rotation, and refixation. Besides possessing surgical skill, every surgeon working in the field of aesthetic surgery must have a "concept of beauty" as defined by Connell and Levy, i.e., the surgeon must recognize the entirety of the face as an aesthetic unit and plan each intervention on an individual basis. Thus, in many cases it is not only necessary to correct the cheek and neck area, but also to take the forehead/eyebrow section into consideration.

[Differential diagnosis and treatment of cheilognathopalatoschises]. / Differenzialdiagnostik und Therapie der Lippen-Kiefer-Gaumen-Spalten.

Cleft lip, alveolous and palate is the second frequent malformation in Europe with an incidence of 1 : 500. Pertaining to ontogeny it must be differentiated between cleft lip and alveolous and cleft palate. Cleft lip and cleft lip and alveolous can occur unilateral, right or left, or bilateral. Cleft bony palate can also occur unilateral, right or left, or bilateral, but cleft velum only in the median plane. Diagnostic and treatment of cleft lip and palate call for interdisciplinary cooperation between gynecologist/obstetrician, cranio-maxillo-facial surgeon, pediatrician, otorhinolaryngologist, orthodontist and logopedist. The schedule of primary cleft surgery in Germany is marked by a more-stage concept, in which at the end of the second year of life cleft lip and palate except cleft alveolous should be closed up. Despite of most careful surgery patients with cleft lip and palate can show functional and aesthetic disturbances. The functional disorders can affected masticatory function, speech, hearing and nasal breathing. Aesthetics disorders can be concerned to skeletal or soft tissue deformities of lip and nose. Operative corrections of bone and soft tissue can rehabilitate these patients entirely from functional and aesthetic view.

Adenovirus L4-100K assembly protein is a granzyme B substrate that potently inhibits granzyme B-mediated cell death.

Cytotoxic lymphocytes kill virus-infected target cells and play a critical role in host recovery from viral infections. Granzyme B (GrB) is a cytotoxic lymphocyte granule protease that plays a critical role in mediating cytotoxicity. In these studies, we demonstrate that the adenovirus assembly protein L4--100K (100K) is a GrB substrate that prevents cytotoxic lymphocyte granule-induced apoptosis in infected target cells by potently inhibiting GrB. This inhibition is absolutely dependent on Asp-48 in 100K, found within a classic GrB consensus motif. 100K is the first viral protein described that exclusively targets the GrB pathway. It represents a novel class of viral protease inhibitor, in which an essential, multifunctional viral protein, which is vulnerable to specific proteolysis by GrB, expresses inhibitory function against that protease.

The three-dimensional structure of human granzyme B compared to caspase-3, key mediators of cell death with cleavage specificity for aspartic acid in P1.

BACKGROUND: Granzyme B, one of the most abundant granzymes in cytotoxic T-lymphocyte (CTL) granules, and members of the caspase (cysteine aspartyl proteinases) family have a unique cleavage specificity for aspartic acid in P1 and play critical roles in the biochemical events that culminate in cell death. RESULTS: We have determined the three-dimensional structure of the complex of the human granzyme B with a potent tetrapeptide aldehyde inhibitor. The Asp-specific S1 subsite of human granzyme B is significantly larger and less charged than the corresponding Asp-specific site in the apoptosis-promoting caspases, and also larger than the corresponding subsite in rat granzyme B. CONCLUSIONS: The above differences account for the variation in substrate specificity among granzyme B, other serine proteases and the caspases, and enable the design of specific inhibitors that can probe the physiological functions of these proteins and the disease states with which they are associated.

[Esthetic facial surgery]. / Asthetische Gesichtschirurgie.

In the last few years, aesthetic facial surgery--especially soft-tissue surgery--has received increasing attention, not only from the medical profession but also particularly from the media. This is due, in part, to the growing level of general acceptance of the formerly stigmatized issue of aesthetic surgery, and in part to increasing patient expectations. Moreover, the introduction of less invasive procedures with outstanding long-term results have brought about a considerable change in aesthetic surgery. A comprehensive account of face lifting, forehead lifting, brow lifting, blepharoplasty, cervical liposuction and adjuvant techniques of skin rejuvenation will be given and discussed.

[Augmentation of the extremely atrophied maxilla and mandible by autologous calvarial bone transplantation]. / Aufbau des extrem atrophierten Ober- und Unterkiefers durch autologe Kalottenknochentransplantate.

Rehabilitation in patients with severe alveolar ridge atrophy of the maxilla or mandible is problematic and can often only be achieved by long-term treatment. In most cases, autologous bone grafting with iliac crest bone has been used to augment severely atrophied upper jaws. In our experience, iliac bone grafts are less useful, since iliac bone appears to be of inferior quality; in elderly osteoporotic women, the bone is soft, indentable, and of poor osteogenic potency. In our department, we have been using only autologous calvarial bone grafts for augmentation of alveolar ridge atrophy since 1993. The bone is removed from the outer table of the skull only, trimmed to the alveolar ridge, und fixed with titanium lag scews. The skull defect created is covered with crushed bone or a titanium mesh to avoid aesthetic problems. Insertion of dental implants follows after a healing period of the bone grafts of 5-6 months. A total of 63 patients underwent calvarial split-graft augmentation; augmentation of the maxilla and mandible was carried out in 15 of these patients, of the maxilla only in eight, and of the mandible only in 40. The investigations 1 year later showed a resorption rate of approximately 10%. This is lower than when using iliac bone grafting. The resorption results were stable between 6 and 12 months after augmentation. Using dental implants (12 patients with 32 implants), the resorption rate was low and constant. We have never seen total loss of bone grafts or intracranial complications. All patients were pleased with the treatment. In our opinion, severe alveolar atrophy of the maxilla or mandible should be compensated for by augmentation with autologous calvarial bone grafts to obtain good long-term results.

[Significance of hemodynamic parameters of blood loss in orthognathic surgery]. / Bedeutung hämodynamischer Parameter für den Blutverlust in der Dysgnathiechirurgie.

INTRODUCTION: The hemodynamic parameters of 95 patients undergoing maxillary or bimaxillary orthognathic surgery in 1996 and 1997 at the Department of OMF Surgery/Plastic Surgery, Krefeld, Germany, were analyzed retrospectivly to study the effect of intraoperative blood loss. MATERIALS AND METHODS: The parameters included the blood loss volume, age, weight and sex of the patients, the mode of osteotomy and the operation time, the surgeon, the average blood pressure, the infusion volume, the anesthesiologist, the thrombocyte counts and their function, the activity of the coagulation factors II, V, VII, VIII, IX, X, XI, XII, XIII and von-Willebrand-factor, and the pathological coagulation factor counts of each patient, the rate of autologous blood donation and the rate of retransfusion. Statistical analysis was done using the Speraman-Rhotest. RESULTS: The average blood loss during maxillary osteotomy was 670 +/- 380 ml and during bimaxillary surgery 1120 +/- 510 ml. Men lost about 300 ml more than women. Operations of more than 3.5 h in length led to a blood loss of 1200 +/- 520 ml as opposed to 670 +/- 310 ml. The average blood loss among various surgeons was between 670 ml and 1180 ml of various anesthesiologists between 730 ml and 1200 ml, without statistical evidence. Some 17.9% of patients showed pathological thrombocytic function concerning medication with aspirin; 34.7% had pathological activities of coagulation factors, but only 2.1% with clinical significance. CONCLUSION: Mode of operation, maxillary or bimaxillary, und length of operation were the most significant factors of intraoperative blood loss. Patients with pathological coagulation had nearly the same rate of blood loss as patients with physiological coagulation. In most cases this was determined by restriction of aspirin. Analysis of the rate of autologous blood retransfusion showed a significant correlation to blood loss in bimaxillary surgery. Maxillary osteotomy led to a retransfusion of only 14.2% of autologous blood unit. This should be reviewed critically especially concerning costs.

Cloning, expression and characterization of rhesus macaque types 1 and 2 5alpha-reductase: evidence for mechanism-based inhibition by finasteride.

The rhesus macaque types 1 and 2 5alpha-reductase (5aR1 and 5aR2) were cloned and expressed in COS cells to facilitate comparison of rhesus and human 5aRs. The deduced protein sequences of the rhesus SaRs shared 94% and 96% identity with the human type 1 and 2 isozymes, respectively. Despite a four amino acid insertion at the N-terminal region of rhesus 5aR1, the biochemical properties of rhesus and human homologs are very similar with respect to pH optimum, Km values for testosterone and progesterone, and inhibition by a variety of inhibitors. As expected, the biochemical properties of the human and rhesus 5aR2 are also very similar. The mechanism of inhibition of the rhesus 5aR1 and 5aR2 by finasteride was investigated in more detail. Finasteride displays time dependent inhibition of the rhesus 5aR1 and 5aR2 with second order rate constants of 4 x 10(3) M(-1) s(-1) and 5.2 x 10(5) M(-1)s(-1). Inhibition of rhesus 5aR2 with 3H-finasteride resulted in 3H bound to the enzyme which is not released by dialysis. Heat denaturation of the [rhesus SaR2:inhibitor] complex releases dihydrofinasteride, a breakdown product presumably related to the NADP+-adduct previously identified with the human SaRs (Bull et al., Mechanism-based inhibition of human steroid 5alpha-reductase by finasteride: Enzyme catalyzed formation of NADP-dihydrofinasteride, a potent bisubstrate analog inhibitor. J. Amer. Chem. Soc., 1996, 118, 2359-2365). Taken together, these results provide good evidence that the rhesus macaque is a suitable model to evaluate the pharmacological properties of finasteride and other 5aR inhibitors.

Rustmicin, a potent antifungal agent, inhibits sphingolipid synthesis at inositol phosphoceramide synthase.

Rustmicin is a 14-membered macrolide previously identified as an inhibitor of plant pathogenic fungi by a mechanism that was not defined. We discovered that rustmicin inhibits inositol phosphoceramide synthase, resulting in the accumulation of ceramide and the loss of all of the complex sphingolipids. Rustmicin has potent fungicidal activity against clinically important human pathogens that is correlated with its sphingolipid inhibition. It is especially potent against Cryptococcus neoformans, where it inhibits growth and sphingolipid synthesis at concentrations <1 ng/ml and inhibits the enzyme with an IC50 of 70 pM. This inhibition of the membrane-bound enzyme is reversible; moreover, rustmicin is nearly equipotent against the solubilized enzyme. Rustmicin was efficacious in a mouse model for cryptococcosis, but it was less active than predicted from its in vitro potency against this pathogen. Stability and drug efflux were identified as two factors limiting rustmicin's activity. In the presence of serum, rustmicin rapidly epimerizes at the C-2 position and is converted to a gamma-lactone, a product that is devoid of activity. Rustmicin was also found to be a remarkably good substrate for the Saccharomyces cerevisiae multidrug efflux pump encoded by PDR5.

[Value of genioplasty as a profile improving intervention in esthetic facial surgery]. / Bedeutung der Genioplastik als profilverbessernder Eingriff in der ästhetischen Gesichtschirurgie.

Genioplasty with rigid fixation using miniplates, preservation of vascular supply and accurate refixation of the soft tissue results in accurately predictable and stable bone and soft tissue contours. The Krefeld study of 36 patients who underwent genioplasty showed a consistent ratio of 85:100 of soft tissue to bone by advancement genioplasty and a 81:100 ratio by set back genioplasty.

Inhibition of rat alpha-reductases by finasteride: evidence for isozyme differences in the mechanism of inhibition.

The mechanism of inhibition of the rat types 1 and 2 5alpha-reductase by finasteride was investigated using recombinantly expressed enzymes. These studies revealed that finasteride is a potent, reversible inhibitor of the rat type 1 5alpha-reductase with Ki=10.2+/-1.3 nM. Finasteride is a potent inhibitor of the rat type 2; however, in this case the compound binds to the type 2 isozyme-NADPH complex to form a ternary complex with Ki=1.19+/-0.10 nM, which then rearranges to a high affinity complex (E:I) with a pseudo first order rate constant of 1.62+/-0.22 x 10(-3)/s. The second order rate constant is k3/Ki=1.37+/-0.31 x 10(6) M/s. Heat denaturation of the (type 2 enzyme:inhibitor) complex releases dihydrofinasteride and presumably the NADP+-adduct previously identified with the human 5alpha-reductases. The effects of finasteride were also studied in intact COS cells transiently expressing the rat types 1 and 2 5alpha-reductase. Results with whole cell assays confirm differences in mechanism of inhibition of rat types 1 and 2 5alpha-reductase by finasteride.

Khafrefungin, a novel inhibitor of sphingolipid synthesis.

In the course of screening for antifungal agents we have discovered a novel compound isolated from an endophytic fungus that inhibits fungal sphingolipid synthesis. Khafrefungin, which is composed of aldonic acid linked via an ester to a C22 modified alkyl chain, has fungicidal activity against Candida albicans, Cryptococcus neoformans, and Saccharomyces cerevisiae. Sphingolipid synthesis is inhibited in these organisms at the step in which phosphoinositol is transferred to ceramide, resulting in accumulation of ceramide and loss of all of the complex sphingolipids. In vitro, khafrefungin inhibits the inositol phosphoceramide synthase of C. albicans with an IC50 of 0.6 nM. Khafrefungin does not inhibit the synthesis of mammalian sphingolipids thus making this the first reported compound that is specific for the fungal pathway.

UDP-N-acetylglucosamine acyltransferase of Escherichia coli. The first step of endotoxin biosynthesis is thermodynamically unfavorable.

UDP-N-acetylglucosamine acyltransferase of Escherichia coli catalyzes the reaction, UDP-GlcNAc + R-3-hydroxymyristoyl-ACP--> UDP-3-O-(R-3-hydroxymyristoyl)-GlcNAc + ACP. Using Matrex Gel Green A and heparin-agarose, we have purified the enzyme to near homogeneity from a strain that overproduces it 474-fold. The subunit molecular mass determined by SDS-gel electrophoresis is approximately 30 kDa, consistent with results of previous radiolabeling experiments in mini-cells. The amino-terminal sequence (Met-Ile-Asp-Lys-Ser-Ala-Phe-Val-His-Pro) and the amino acid composition of the purified protein are consistent with DNA sequencing (Coleman, J., and Raetz, C. R. H. (1988) J. Bacteriol. 170, 1268-1274). At saturating concentrations of the second substrate, the apparent Km values for UDP-GlcNAc and R-3-hydroxymyristoyl-ACP are 99 and 1.6 microM, respectively. There is an absolute requirement for the R-3-hydroxy moiety of the fatty acyl-ACP substrate; myristoyl-ACP binds effectively (IC50 = 2 microM) but is inactive (< 0.01%) as an alternate substrate. The most remarkable feature of the reaction is its unfavorable equilibrium constant, Keq approximately equal to 0.01, which is not predicted by model S-->O acyl transfer reactions. Thus, although UDP-GlcNAc acyltransferase catalyzes the first unique step of lipid A biosynthesis, it is the second enzyme (the deacetylase) that commits the substrates to this pathway. The specific activity of the deacetylase is elevated approximately 5-fold when lipid A synthesis is inhibited.

Inhibition of 3-hydroxy-3-methylglutaryl-CoA synthase and cholesterol biosynthesis by beta-lactone inhibitors and binding of these inhibitors to the enzyme.

The beta-lactones L-659,699 [(E,E)-11-[3-(hydroxymethyl)-4-oxo-2- oxetanyl]-3,5,7-trimethyl-2,4-undecadienoic acid) and its radioactive derivative 3H-L-668,411 (the 2,3-ditritiated methyl ester of L-659,699) inhibited a partially purified preparation of rat liver cytosolic 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase with an IC50 of 0.1 microM. These compounds were also found to inhibit the incorporation of [14C]acetate into sterols in cultured Hep G2 cells with an IC50 of 3 microM. New kinetic evidence indicated that inhibition of the isolated enzyme was irreversible. In contrast, sterol biosynthesis in cultured Hep G2 cells was rapidly restored upon removal of the compound from the medium of inhibited cultures, suggesting reversibility of inhibition in the cells. Radioactivity was found to be associated with a single cytoplasmic protein by SDS/PAGE of the cytoplasm of Hep G2 cells after incubation of the cells with the inhibitor 3H-L-668,411. This protein was identified as cytoplasmic HMG-CoA synthase. Binding of the radioactive compound to the enzyme was decreased with time if the radioactive inhibitor was removed from the medium. Exposure of a gel containing the radioactive enzyme-inhibitor complex to neutral hydroxylamine also resulted in a loss of radioactivity from the gel. The purified rat liver enzyme reacted with the 3H-ligand to form a stable enzyme-inhibitor complex which could be isolated by h.p.l.c. Radioactivity was also subsequently lost from this complex when it was incubated with neutral hydroxylamine. Incorporation of [14C]acetate into cholesterol in mouse liver was inhibited in a reversible manner after oral administration of the beta-lactone inhibitor. These studies, as well as the kinetic evidence presented, suggest that the beta-lactone inhibitors acylate HMG-CoA synthase in a reaction which appears to be irreversible in vitro, but is easily reversed in cultured cells and in animals.

A novel heterodimeric cysteine protease is required for interleukin-1 beta processing in monocytes.

Interleukin-1 beta (IL-1 beta)-converting enzyme cleaves the IL-1 beta precursor to mature IL-1 beta, an important mediator of inflammation. The identification of the enzyme as a unique cysteine protease and the design of potent peptide aldehyde inhibitors are described. Purification and cloning of the complementary DNA indicates that IL-1 beta-converting enzyme is composed of two nonidentical subunits that are derived from a single proenzyme, possibly by autoproteolysis. Selective inhibition of the enzyme in human blood monocytes blocks production of mature IL-1 beta, indicating that it is a potential therapeutic target.

Mechanism-based inactivation of alanine racemase by 3-halovinylglycines.

Alanine racemase, an enzyme important to bacterial cell wall synthesis, is irreversibly inactivated by 3-chloro- and 3-fluorovinylglycine. Using alanine racemase purified to homogeneity from Escherichia coli B, the efficient inactivation produced a lethal event for every 2.2 +/- 0.2 nonlethal turnovers, compared to 1 in 800 for fluoroalanine. The mechanism of inhibition involves enzyme-catalyzed halide elimination to form an allenic intermediate that partitions between reversible and irreversible covalent adducts, in the ratio 3:7. The reversible adduct (lambda max = 516 nm) decays to regenerate free enzyme with a half-life of 23 min. The lethal event involves irreversible alkylation of a tyrosine residue in the sequence -Val-Gly-Tyr-Gly-Gly-Arg. The second-order rate constant for this process with D-chlorovinylglycine (122 +/- 14 M-1 s-1), the most reactive analog examined, is faster than the equivalent rate constant for D-fluoroalanine (93 M-1 s-1). The high killing efficiency and fast turnover of these mechanism-based inhibitors suggest that their design, employing the haloethylene moiety to generate a reactive allene during catalysis, could be extended to provide useful inhibitors of a variety of enzymes that conduct carbanion chemistry.

Antistasin, a leech-derived inhibitor of factor Xa. Kinetic analysis of enzyme inhibition and identification of the reactive site.

Antistasin is a 119-amino acid protein isolated from the salivary glands of the Mexican leech Haementeria officinalis. The determination of the primary structure of antistasin revealed that the protein is highly disulfide-bonded with a 2-fold internal homology. Antistasin exhibits a potent anticoagulant activity purportedly due to the selective inhibition of Factor Xa (Tuszinsky, G. P., Gasic, T. B., and Gasic, G. J. (1987) J. Biol. chem. 262, 9718-9723). In the present study a detailed kinetic analysis of the inhibitory interaction between antistasin and Factor Xa was performed. In addition, the specificity of antistasin was examined by testing its ability to inhibit a variety of serine proteinases. Utilizing purified antistasin and a tripetidyl p-nitroanilide substrate, antistasin was shown to act as a reversible inhibitor of Factor Xa which exhibits slow-tight binding kinetics. Antistasin reacts stoichiometrically with Factor Xa with inhibition displaying a mixed, primarily competitive type. The inhibition is partial in the presence of Ca2+ and becomes complete in the absence of Ca2+. The estimated dissociation constant for the enzyme-inhibitor complex is between 0.31 and 0.62 nM. After binding to Factor Xa, antistasin is cleaved at a single site to yield a modified inhibitor. Automated gas-phase sequence analysis of the modified inhibitor indicates the arginine residue at position 34 in antistasin occupies the P1 position of the reactive site. These data indicate that the leech has evolved a highly selective and potent inhibitor of coagulation Factor Xa that shares several mechanistic similarities with other serine proteinase inhibitors.

Phosphinic acid inhibitors of D-alanyl-D-alanine ligase.

We report the synthesis of a series of phosphinic acid dipeptide analogues, NH2CH(R1)PO(OH)CH2CH(R2)CO2H, related to DAla-DAla. The best of these compounds are potent, essentially irreversible inhibitors of DAla-DAla ligase, and their preferred stereochemistry was shown by chiral synthesis of (1(S)-aminoethyl)(2(R)-carboxy-1-n-propyl)phosphinic acid, 12b, and by X-ray crystallography of its derivative benzyl [1(S)-[(benzyloxycarbonyl)-amino]ethyl](2(R)-carbomethoxy-1-propyl) phosphinate, 13, to correspond to the stereochemical configuration of DAla-DAla at both centers. A mechanism for the inhibition of DAla-DAla ligase by these compounds is proposed to involve an ATP-dependent formation of phosphorylated inhibitor within the enzyme's active site. The antibacterial activities of these compounds are modest although their spectra include both Gram-positive and Gram-negative susceptible organisms. The best antibacterial activity was shown by (1(S)-aminoethyl) [2-carboxy-2(R)-(methylthio)-1-ethyl]phosphinic acid, 3e, whose MIC's range from 4-128 micrograms/mL on nine of a panel of 11 bacterial organisms. Combination of one of the more active phosphinic acids 12b with the alanine racemase inhibitor fluoro-D-alanine enhances the antibacterial spectrum of the latter on several strains of bacteria and inhibits fluoro-D-alanine's self-reversal, which normally occurs at concentrations several fold higher than its MIC level. This inhibition of fluoro-D-alanine self-reversal is consistent with an involvement of DAla-DAla ligase inhibition in the antibacterial activity of these compounds.

Antibacterial activities of fluorovinyl- and chlorovinylglycine and several derived dipeptides.

The in vitro antibacterial activities of several halovinylglycine compounds and their L-norvalyl peptide derivatives are presented. The most potent of them, L-norvalyl-L-chlorovinylglycine, displayed good activity against gram-positive organisms, including methicillin-resistant Staphylococcus species. Chlorovinylglycine is an efficient inhibitor of alanine racemase, but the antibacterial activity of L-norvalyl-L-chlorovinylglycine may involve other physiological targets as well.