[Exchange of aniridia IOLs for customized iris IOL implants]. / Austausch von Aniridie-IOL gegen individuelle Iris-IOL-Implantate.

BACKGROUND: Three groups of iris prostheses can be distinguished for the surgical treatment of iris defects: (1) segmental iris implants, (2) combined iris diaphragm intraocular lenses (IOL) and (3) pure iris implants. Most iris reconstructions are accompanied by aphakia correction with secondary IOL implantation. Although the primary goal is to create a pupil and to improve glare perception, contrast sensitivity and visual acuity, the esthetic result is also a relevant component. OBJECTIVE: Functional and esthetic results after replacement of an aniridia IOL implant with a custom-made artificial iris with IOL. MATERIAL AND METHODS: In this retrospective study with seven eyes from seven patients, an iris diaphragm IOL (Morcher GmbH, Stuttgart, Germany) was exchanged for medical reasons (subluxation) against a custom-made artificial iris made of silicone (ArtificialIris, HumanOptics, Erlangen, Germany) in combination with a sutured IOL. The follow-up period was at least 3 months. Best corrected distance visual acuity (BCVA), endothelial cell count (ECC), complications, glare perception as well as esthetic outcome and patient satisfaction were evaluated. RESULTS: The BCVA and ECC showed no statistically significant change between the preoperative and postoperative values (p > 0.05). There was a decentration of the iris IOL implant of 0.27 ± 0.19 mm three months postoperatively. On a visual analogue scale (VAS) from 1 to 10 (1 = not satisfied at all, 10 = extremely satisfied), satisfaction with the overall result was rated 8.6 ± 2.5. Subjective glare perception improved to 5.6 ± 3.5 and subjective esthetic impairment improved to 2.4 ± 2.0 on the VAS (1 = none, 10 = extremely strong). Postoperative complications included transient intraocular hypotonia in two eyes, intraocular pressure increase in two eyes, retinal detachment and transient vitreous hemorrhage in one eye each. Of the seven patients six would repeat the procedure. CONCLUSION: Compared to a rigid aniridia IOL implant, replacement with a custom-made artificial iris in combination with an IOL provides not only a good functional result but simultaneously also an esthetically pleasing result.

Experimental data of thermal cracking of soybean oil and blends with hydrogenated fat.

This article presents the experimental data on the thermal cracking of soybean oil and blends with hydrogenated fat. Thermal cracking experiments were carried out in a plug flow reactor with pure soybean oil and two blends with hydrogenated fat to reduce the degree of unsaturation of the feedstock. The same operational conditions was considered. The data obtained showed a total aromatics content reduction by 14% with the lowest degree of unsaturation feedstock. Other physicochemical data is presented, such as iodine index, acid index, density, kinematic viscosity. A distillation curve was carried out and compared with the curve from a petroleum sample.

Characterization of an Indonesian isolate of Paecilomyces reniformis.

An entomopathogenic fungus (IndGH 96), identified as Paecilomyces reniformis, was isolated from long-horned grasshoppers (Orthoptera: Tettigoniidae) in Sulawesi, Indonesia. The phenotypic and molecular data identified the IndGH 96 as a P. reniformis. We present the first comprehensive characterization of this species using morphological features, sequencing of the ITS1-5.8s-ITS2 region, D1/D2 region of 28S of rDNA, and a portion of the tubulin gene, and laboratory bioassays. Distinguishing features include a hyphal body stage during vegetative growth and the production of distinctly curved, light-green conidia. High dosage bioassays showed that IndGH 96 was infectious to both long-horned and short-horned grasshoppers but not to the house cricket, Acheta domestica, or to the lepidopterans velvetbean caterpillar, Anticarsia gemmatalis or fall armyworm, Spodoptera frugiperda. Phenotypic and genetic analyses suggest that IndGH 96 and other isolates of P. reniformis are more closely related to Nomuraea rileyi than to other species of Paecilomyces.

Gene expression profiles among immature and adult reproductive castes of the termite Reticulitermes flavipes.

Array-based genomic studies were conducted with the goal of identifying immature (i.e. nymph) and adult reproductive caste-biased gene expression in the termite Reticulitermes flavipes. Using cDNA macro-arrays, we identified thirty-four nymph-biased genes falling into eight ontogenic categories. Based on gene expression profiles among diverse castes and developmental stages (determined by quantitative PCR), several important trends emerged. These findings highlight the importance of several developmental and survival-based factors among immature and adult termite reproductives, including: vitellogenesis, nutrient storage, juvenile hormone sequestration, ribosomal translational and filtering mechanisms, fatty acid biosynthesis, apoptosis inhibition, and both endogenous and symbiont cellulase-assisted nutrition. These findings are highly significant as they are the first to elucidate the molecular biology underlying termite reproductive caste differentiation and reproductive caste-specific biology. Other gene expression results are in agreement with previous findings that suggest roles for vitellogenin-like haemolymph proteins in soldier caste differentiation.

Membrane structural perturbations caused by anesthetics and nonimmobilizers: a molecular dynamics investigation.

The structural perturbations of the fully hydrated dimyristoyl-phosphatidylcholine bilayer induced by the presence of hexafluoroethane C(2F6), a "nonimmobilizer," have been examined by molecular dynamics simulations and compared with the effects produced by halothane CF3CHBrCl, an "anesthetic," on a similar bilayer (DPPC) (Koubi et al., Biophys. J. 2000. 78:800). We find that the overall structure of the lipid bilayer and the zwitterionic head-group dipole orientation undergo only a slight modification compared with the pure lipid bilayer, with virtually no change in the potential across the interface. This is in contrast to the anesthetic case in which the presence of the molecule led to a large perturbation of the electrostatic potential across to the membrane interface. Similarly, the analysis of the structural and dynamical properties of the lipid core are unchanged in the presence of the nonimmobilizer although there is a substantial increase in the microscopic viscosity for the system containing the anesthetic. These contrasting perturbations of the lipid membrane caused by those quite similarly sized molecules may explain the difference in their physiological effects as anesthetics and nonimmobilizers, respectively.

Maharishi Vedic vibration technology on chronic disorders and associated quality of life.

There is a growing interest for more effective, innovative programs to address the chronic illness suffered by approximately 40 percent of the U.S. population. The purpose of this study was to evaluate the effects of a new Maharishi Vedic Medicine program-the Maharishi Vedic Vibration Technology-on the quality of life of individuals with chronic disorders. A total of 213 individuals took part in the study (mean age=48.55 years; average length of time of chronic illness=18.42 years). Results showed that over three sessions, the average self-reported improvement in chronic illness was 40.97 percent. Conditions related to neck pain improved the most (51.25%), followed by respiratory ailments (48.00%), digestive problems (46.90%), mental health, including anxiety and depression (46.34%), arthritis (41.57%), insomnia (37.38%), back pain (36.32%), headaches (35.83%), cardiovascular conditions (22.31%), and eye problems (21.19%). Findings also showed significant reductions in frequency of discomfort or pain (p<.000001), intensity of discomfort (p<.000001), and disabling effects of the discomfort in daily activity (p<.000001), in addition to overall improvement in mental health (p<.000001) and vitality (p<.000125). Possible mechanisms of action are presented.

Transgene and transposon silencing in Chlamydomonas reinhardtii by a DEAH-box RNA helicase.

The molecular mechanism(s) responsible for posttranscriptional gene silencing and RNA interference remain poorly understood. We have cloned a gene (Mut6) from the unicellular green alga Chlamydomonas reinhardtii that is required for the silencing of a transgene and two transposon families. Mut6 encodes a protein that is highly homologous to RNA helicases of the DEAH-box family. This protein is necessary for the degradation of certain aberrant RNAs, such as improperly processed transcripts, which are often produced by transposons and some transgenes.

Molecular dynamics simulation of four-alpha-helix bundles that bind the anesthetic halothane.

The mutation of a single leucine residue (L38) to methionine (M) is known experimentally to significantly increase the affinity of the synthetic four-alpha-helix bundle (Aalpha(2))(2) for the anesthetic halothane. We present a molecular dynamics study of the mutant (Aalpha(2)-L38M)(2) peptide, which consists of a dimer of 62-residue U-shaped di-alpha-helical monomers assembled in an anti topology. A comparison between the simulation results and those obtained for the native (Aalpha(2))(2) peptide indicates that the overall secondary structure of the bundle is not affected by the mutation, but that the side chains within the monomers are better packed in the mutant structure. Unlike the native peptide, binding of a single halothane molecule to the hydrophobic core of (Aalpha(2)-L38M)(2) deforms the helical nature of one monomer in a region close to the mutation site. Increased exposure of the cysteine side chain to the hydrophobic core in the mutant structure leads to the enhancement of the attractive interaction between halothane and this specific residue. Since the mutated residues are located outside the hydrophobic core the observed increased affinity for halothane appears to be an indirect effect of the mutation.

Distribution of halothane in a dipalmitoylphosphatidylcholine bilayer from molecular dynamics calculations.

We report a 2-ns constant pressure molecular dynamics simulation of halothane, at a mol fraction of 50%, in the hydrated liquid crystal bilayer phase of dipalmitoylphosphatidylcholine. Halothane molecules are found to preferentially segregate to the upper part of the lipid acyl chains, with a maximum probability near the C(5) methylene groups. However, a finite probability is also observed along the tail region and across the methyl trough. Over 95% of the halothane molecules are located below the lipid carbonyl carbons, in agreement with photolabeling experiments. Halothane induces lateral expansion and a concomitant contraction in the bilayer thickness. A decrease in the acyl chain segment order parameters, S(CD), for the tail portion, and a slight increase for the upper portion compared to neat bilayers, are in agreement with several NMR studies on related systems. The decrease in S(CD) is attributed to a larger accessible volume per lipid in the tail region. Significant changes in the electric properties of the lipid bilayer result from the structural changes, which include a shift and broadening of the choline headgroup dipole (P-N) orientation distribution. Our findings reconcile apparent controversial conclusions from experiments on diverse lipid systems.

A designed four-alpha-helix bundle that binds the volatile general anesthetic halothane with high affinity.

The structural features of volatile anesthetic binding sites on proteins are being examined with the use of a defined model system consisting of a four-alpha-helix bundle scaffold with a hydrophobic core. Previous work has suggested that introducing a cavity into the hydrophobic core improves anesthetic binding affinity. The more polarizable methionine side chain was substituted for a leucine, in an attempt to enhance the dispersion forces between the ligand and the protein. The resulting bundle variant has an improved affinity (K(d) = 0.20 +/- 0.01 mM) for halothane binding, compared with the leucine-containing bundle (K(d) = 0.69 +/- 0.06 mM). Photoaffinity labeling with (14)C-halothane reveals preferential labeling of the W15 residue in both peptides, supporting the view that fluorescence quenching by bound anesthetic reports both the binding energetics and the location of the ligand in the hydrophobic core. The rates of amide hydrogen exchange were similar for the two bundles, suggesting that differences in binding affinity were not due to changes in protein stability. Binding of halothane to both four-alpha-helix bundle proteins stabilized the native folded conformations. Molecular dynamics simulations of the bundles illustrate the existence of the hydrophobic core, containing both W15 residues. These results suggest that in addition to packing defects, enhanced dispersion forces may be important in providing higher affinity anesthetic binding sites. Alternatively, the effect of the methionine substitution on halothane binding energetics may reflect either improved access to the binding site or allosteric optimization of the dimensions of the binding pocket. Finally, preferential stabilization of folded protein conformations may represent a fundamental mechanism of inhaled anesthetic action.

Molecular dynamics simulation of a synthetic four-alpha-helix bundle that binds the anesthetic halothane.

The structural features of binding sites for volatile anesthetics are examined by performing a molecular dynamics simulation study of the synthetic four-alpha-helix bundles (Aalpha2)2, which are formed by association of two 62-residue di-alpha-helical peptides. The peptide bundle (Aalpha2)2 was designed by Johansson et al. [Biochemistry 37 (1998) 1421-1429] and was shown experimentally to have a high affinity for the binding of the anesthetic halothane (CF3CBrCIH) in a hydrophobic cavity. Since (Aalpha2)2 can exhibit either the anti or syn topologies, the two distinct bundles are simulated both in the presence and in the absence of halothane. Nanosecond length molecular dynamics trajectories were generated for each system at room temperature (T = 298 K). The structural and dynamic effects of the inclusion of halothane are compared, illustrating that the structures are stable over the course of the simulation; that the (Aalpha2)2 bundles have suitable pockets that can accommodate halothane; that the halothane remains in the designed hydrophobic cavity in close proximity to the Trp residues with a preferred orientation; and that the dimensions of the peptide are perturbed by the inclusion of an anesthetic molecule.

Effects of anesthetics on the structure of a phospholipid bilayer: molecular dynamics investigation of halothane in the hydrated liquid crystal phase of dipalmitoylphosphatidylcholine.

We report the results of constant temperature and pressure molecular dynamics calculations carried out on the liquid crystal (Lalpha) phase of dipalmitoylphosphatidylcholine with a mole fraction of 6.5% halothane (2-3 MAC). The present results are compared with previous simulations for pure dipalmitoylphosphatidylcholine under the same conditions (Tu et al., 1995. Biophys. J. 69:2558-2562) and with various experimental data. We have found subtle structural changes in the lipid bilayer in the presence of the anesthetic compared with the pure lipid bilayer: a small lateral expansion is accompanied by a modest contraction in the bilayer thickness. However, the overall increase in the system volume is found to be comparable to the molecular volume of the added anesthetic molecules. No significant change in the hydrocarbon chain conformations is apparent. The observed structural changes are in fair agreement with NMR data corresponding to low anesthetic concentrations. We have found that halothane exhibits no specific binding to the lipid headgroup or to the acyl chains. No evidence is obtained for preferential orientation of halothane molecules with respect to the lipid/water interface. The overall dynamics of the lipid-bound halothane molecules appears to be reminiscent of that of other small solutes (Bassolino-Klimas et al., 1995. J. Am. Chem. Soc. 117:4118-4129).

Computer simulation study of synthetic 4-helix bundle that binds halothane.

1. The synthetic peptide H10A24 self-assembles in aqueous solution into a 4-helix bundle, which exhibits saturable binding of halothane. 2. Molecular dynamics simulation techniques have been used to study the vacuum structure of this bundle. 3. The simulation, initiated as four ideal parallel alpha-helices, resulted in a compact bundle, whose secondary structure remains predominantly alpha-helical. 4. The hydrophobic core has no apparent pocket large enough to accomodate halothane.

Success rates of osseointegration for implants placed under sterile versus clean conditions.

A retrospective analysis was done comparing the success rate of osseointegration at stage 2 of implants placed under "sterile" versus "clean" conditions. "Sterile" surgery took place in an operating room setting with strict sterile protocol. "Clean" surgery took place in a clinic setting with the critical factor that nothing touched the surface of the implant until it contacted the prepared bone site. A total of 273 implants in 61 cases were placed under sterile conditions with a fixture success rate of 98.9% and a case success rate of 95.1%; 113 implants were placed under clean conditions in 31 cases with a fixture and case success rate of 98.2% and 93.5%, respectively as judged clinically at stage 2. The difference in the success rates was not statistically significant. The results of this analysis indicate that implant surgery can be performed under both "sterile" and "clean" conditions to achieve the same high rate of clinical osseointegration.

The effect of crestal versus mucobuccal incisions on the success rate of implant osseointegration.

A retrospective analysis compared the success rate of osseointegration of Nobelpharma implants at stage 2 surgery. The implants had been placed using either a mucobuccal fold incision or a crestal incision. A total of 386 implants was placed in 92 patients; 265 implants were placed in 60 patients using a mucobuccal fold incision, with a success rate of 98.8%, and 121 implants were placed in 32 patients using a crestal incision, with a success rate of 98.3%. Implants can be placed using either a mucobuccal fold incision or a crestal incision to achieve predictable success.

Role of industry representatives in providing assistance to certified diabetes educators.

OBJECTIVE: As diabetes educators have become more frequently involved in decisions regarding medications, equipment, and supplies, industry representatives have increasingly provided various types of assistance. The major objectives of this survey were to determine 1) the types of assistance being provided to certified diabetes educators (CDEs) by industry representatives, 2) whether product recommendations are based on assistance provided, and 3) the types of assistance that CDEs consider appropriate. RESEARCH DESIGN AND METHODS: We developed the survey instrument and it was mailed to every fifth person listed in the 1989 directory of CDEs. Three hundred twenty-five (51%) of the active surveys were returned. RESULTS: Those responding indicated that 1) the types of support provided most frequently by industry representatives include instructional materials, samples, supplies, and equipment for patient care and education; 2) the number of types of support provided is directly related to the number of industry representatives seen on a regular basis and the frequency of interaction; 3) 22% of the educators state that they make product recommendations based on support provided; and 4) the role of the industry reps should be to continue support for patient care and education, to provide more support for public and professional education, and to minimize support for personal items, e.g., gifts or meals. CONCLUSIONS: The survey indicates that CDEs are receiving many types of assistance from industry representatives and that they prefer that such assistance be targeted toward patient and professional education.

Modified roll technique for localized alveolar ridge augmentation.

A modification of Abram's roll technique is described. A "trap-door" approach is used to reflect and preserve the epithelium that overlies the connective tissue pedicle; the epithelial pedicle is used to cover the donor site. Two case reports illustrate the technique.

Lipomas of the mesencephalic tectum and rostral pons associated with sleep apnea syndrome.

Two patients with mixed sleep apnea and autopsy-documented lipomas of the mesencephalic tectum and rostral pons are presented. Microscopically, the locus ceruleus was unilaterally invaded by a tumor in one case and may have been compressed in the other. Adipocytes and fibrous tissue were present adjacent to pial surfaces and around small blood vessels within the parenchyma. There was prominent astrogliosis in the adjacent neuropil. Although respiratory control is a complex, multifocal phenomena, these findings raise the possibility that the locus ceruleus or adjacent brain stem regions may be affected in some instances of sleep apnea.