Buttressing effects on haloarene deprotonation: a merely kinetic or also thermodynamic phenomenon?

(2,6-Dichlorophenyl)- and (2,6-dibromophenyl)trialkylsilanes undergo hydrogen/metal interconversion preferentially at the 4- rather than 3-position. However, the organometallic species generated by such a "meta metalation" are thermodynamically less stable (i.e.

The tissue response to an alkylene bis(dilactoyl)-methacrylate bone adhesive.

Gluing is an attractive technique to fix small bone fragments. However, to date no bone adhesive could be established successfully for all day clinical use. The purpose of this experimental study was to investigate the biocompatibility of a new bone glue based on alkylene bis(dilactoyl)-methacrylate in 36 rabbits.

[Properties and degradation of a new bioresorbable bone glue].

In trauma surgery gluing is an attractive method of bonding fractured bone, which is rapid and does not require the use of screws and plates. The purpose of this study was to analyze in vitro the properties of a new bioresorbable bone glue, and in vivo its structure and degradation. The newly developed bone glue is based on alkylenbis(oligolactoyl)methacrylates and employs a two-component initiator system.

Conjugated linoleic acid: health implications and effects on body composition.

Conjugated linoleic acid (CLA) is attracting interest because of its purported effects on body composition, specifically a reduction in body fat mass and an increase in lean body mass. Other reported beneficial health-related effects of CLA include anticarcinogenic, antiatherogenic, antidiabetogenic, and immune modulating properties. Because research on CLA has been almost exclusively in animals and the mechanism(s) by which CLA exerts its effects remain largely unknown, scientists are extremely cautious about making definitive statements about CLA.

In vivo mechanisms of hydroxyapatite ceramic degradation by osteoclasts: fine structural microscopy.

In the present study the in vivo mechanism of calcium-phosphate (CaP) ceramic degradation has been investigated by means of transmission electron microscopy. The results revealed osteoclast-mediated degradation of hydroxyapatite ceramic implanted into sheep bone by simultaneous resorption and phagocytosis. After 6 weeks of implantation, osteoclasts were localized immediately beneath the ceramic surface.

Value of micro-CT as an investigative tool for osteochondritis dissecans.

Purpose: To evaluate micro computed tomography (micro-CT) for the assessment of osteochondritis dissecans in comparison with histology.

Material And Methods: Osteochondritis dissecans lesions of 3 patients were evaluated using micro-CT (0.125 mA, 40 keV, 60 microm slice thickness, 60 microm isotropic resolution, entire sample) and light microscopy (toluidine blue, 3-5 microm slice thickness).

Bone ingrowth in bFGF-coated hydroxyapatite ceramic implants.

This experimental study was performed to evaluate angiogenesis, bone formation, and bone ingrowth in response to osteoinductive implants of bovine-derived hydroxyapatite (HA) ceramics either uncoated or coated with basic fibroblast growth factor (bFGF) in miniature pigs. A cylindrical bone defect was created in both femur condyles of 24 miniature pigs using a saline coated trephine. Sixteen of the 48 defects were filled with HA cylinders coated with 50 microg rhbFG, uncoated HA cylinders, and with autogenous transplants, respectively.

Differential effects of bromination on substrates and inhibitors of kynureninase from Pseudomonas fluorescens.

A series of brominated compounds has been synthesized and evaluated as substrates and inhibitors of kynureninase from Pseudomonas fluorescens. Both 3-bromo-L-kynurenine and 5-bromo-L-kynurenine were found to be substrates with similar k(cat) values to L-kynurenine, but the K(m) value for 3-bromo-L-kynurenine is very high (ca. 2 mM) compared to that for 5-bromo-L-kynurenine (11 microM) and L-kynurenine (25 microM).

Self-reported vegetarianism may be a marker for college women at risk for disordered eating.

The purpose of this study was to determine whether differences exist in eating attitudes and behaviors of vegetarian and nonvegetarian college women. The Eating Attitudes Test (EAT) and a questionnaire were used to gather information on eating attitudes and behaviors of 143 female college students. Thirty participants were self-reported vegetarians, and 113 participants were nonvegetarians.

[Ultrastructural examination of cell-mediated degradation of a calcium phosphate ceramic].

Up to now little is known about cell-mediated degradation of biomaterial surfaces, especially as methodologically significant studies are not available. Therefore, the present study focused on ultrastructural details of cells involved in degradation of calcium phosphate ceramics. For the experimental procedure six adult sheep were used.

[Vacuum mixing systems for bone cement completion - comparison of different systems].

Introduction: The use of vacuum mixing systems when mixing bone cement reduces its porosity and hereby significantly improves the features of the material. The currently available mixing systems are compared with regard to handling, mechanical properties and economical aspects.

Methods: In 8 vacuum mixing systems the handling, pump performance, system tightness, the used air volume, the filter efficiency, the remaining amounts in the mixing system and the porosity of the cements are shown in comparison.

Reconstruction of the lower leg with the sural artery flap.

Background: Soft tissue covering on the lower leg is frequently a difficult challenge and causes increasing problems for treatment in smaller hospitals. We introduce a plastic surgery method for covering these soft tissue defects.

Method: An island of skin, centered above the sural nerve, is cut out in the middle dorsal area of the lower leg.

["Biorigid" interlocking after unreamed intramedullary nailing of tibial shaft fractures].

Between April 1996 and December 1999, 76 tibial shaft fractures were treated at the Department of Trauma Surgery of the Justus-Liebig-University in Giessen, Germany and the Department of Orthopedic Surgery of the University of Louisville, USA with a newly developed, unreamed, solid, small diameter tibial nail interlocked "biorigidly" with screws in grooves of the nail. 69 Patients were reviewed with a minimal follow-up period of 16 months. In 65 patients, the fractures united without exchange nailing, although four of these fractures showed a delay of healing.

Evidence for in vivo transport of bioactive nitric oxide in human plasma.

Although hitherto considered as a strictly locally acting vasodilator, results from recent clinical studies with inhaled nitric oxide (NO) indicate that NO can exert effects beyond the pulmonary circulation. We therefore sought to investigate potential remote vascular effects of intra-arterially applied aqueous NO solution and to identify the mechanisms involved. On bolus application of NO into the brachial artery of 32 healthy volunteers, both diameter of the downstream radial artery and forearm blood flow increased in a dose-dependent manner.

[Long-term results in the surgical treatment of pilon tibial fractures. A retrospective study].

Background: While Pilon fractures of the tibia have been treated for decades by primary open reduction and internal fixation by plate osteosynthesis, during the last 10 years differential treatment was developed: After primary open reduction nowadays patients are treated with (according to type of fracture and tissue damage). As well as primary open reduction and internal fixation a two-step treatment (primary external fixator and delayed ORIF) or consolidation by external fixator combined with minimal invasive osteosynthesis (cannulated screws and K-wires) has been implemented. Furthermore, the significance of primary bone grafting in comminuted fractures to prevent aseptic pseudarthrosis has been acknowledged.

Muscarinic receptors in human luteinized granulosa cells: activation blocks gap junctions and induces the transcription factor early growth response factor-1.

Acetylcholine (ACh) was recently described to be produced by and act on human luteinizing granulosa cells (GCs). Cholinergic agents increase intracellular calcium levels and stimulate GC proliferation via muscarinic receptors. Based on this observation and because endocrine cells of the forming human corpus luteum (CL), which are the in vivo counterparts of GCs, also proliferate in vivo, we hypothesized that ACh may be a factor involved in the regulation of the complex cellular events occurring during ovulation and formation of the CL.

CD-ROM nutrient analysis database assists self-monitoring behavior of active duty Air Force personnel receiving nutrition counseling for weight loss.

This study observed the effect of using a computerized vs manual method of self-monitoring among Air Force personnel receiving nutrition counseling for weight loss. Subjects who enrolled during the first 2 weeks of the 4-week recruitment period completed food records for 6 weeks using a CD-ROM nutrient database (intervention group) whereas those who enrolled during the last 2 weeks used a food record booklet (comparison group). Of the 42 subjects (n = 23 intervention group and n = 19 comparison group), only 113 intervention and 11 comparison group subjects (57% of study enrollees) submitted at least 1 food record during the study and were included in the analysis, which included review of pre- and poststudy questionnaires, food records, and focus group data.

Mutation of cysteine-295 to alanine in secondary alcohol dehydrogenase from Thermoanaerobacter ethanolicus affects the enantioselectivity and substrate specificity of ketone reductions.

The mutation of Cys-295 to alanine in Thermoanaerobacter ethanolicus secondary alcohol dehydrogenase (SADH) was performed to give C295A SADH, on the basis of molecular modeling studies utilizing the X-ray crystal structure coordinates of the highly homologous T. brockii secondary alcohol dehydrogenase (1YKF.PDB).

Automated ultrasonic measurement of human arteries for the determination of endothelial function.

Aim: Brachial artery ultrasonography is used to measure flow-mediated dilatation (FMD) as a marker of endothelial function in patients at risk for atherosclerosis. Major disadvantages are the time-consuming manual readings and the high within- and between-observer variability. The authors hypothesize that the ultrasound-based determination of endothelial function can be simplified and refined by an automated analysis system.

Lateral approach with osteotomy of the tibial tubercle in primary total knee arthroplasty.

In a prospective study of 51 patients (61 cases) with primary total knee arthroplasty (valgus knees and/or knees that had undergone previous nonarthroplasty surgery), a lateral approach with osteotomy of the tibial tubercle was performed. In a lateral approach, lateral release techniques form part of the approach. In addition, the medial blood supply to the patella is preserved.

[Polygraphic validation of distraction tasks in clinical differential tremor diagnosis].

In a total of 30 tremor patients (14 with Parkinson's disease, 6 with cerebellar tremor, 4 with essential tremor, 4 with psychogenic tremor, 2 with enhanced physiological tremor), tremor was electromyographically recorded before, during and after contralateral distraction tasks (tapping with the index finger or the tip of the foot, sequential flexion of the 2nd to 5th finger towards the thumb, "keyboarding", and sensory discrimination). 22 of 26 patients with organic tremors spontaneously choose a volitional tapping frequency independent from their tremor frequency. In 4 patients with psychogenic tremor, frequencies of tremor and tapping were locked (n = 3), or tremor disappeared abruptly (n = 1) when contralateral tapping was started.

Sources of error and nutritional adequacy of the food guide pyramid.

The authors assessed the accuracy of college students' use of the Food Guide Pyramid (FGP) in their diets and evaluated sources of error and nutritional adequacy of the pyramid. Students enrolled in an undergraduate nutrition class (N = 346) completed 3-day dietary records that were analyzed, using computer software, to determine individual recommended dietary allowance (RDA) values and the extent to which the students' diets met those values. The students' most common error in using the FGP was underestimating serving sizes.