Surgical treatment of cervical spine fractures in ankylosing spondylitis patients: posterior stabilization using intraoperative CT scanner-based navigation.

INTRODUCTION: The authors analyzed a series of ankylosing spondylitis patients with cervical spine fracture undergoing posterior stabilization using spinal navigation based on intraoperative CT imaging. The purpose of this study was to evaluate the accuracy and safety of navigated posterior stabilization and to analyze the adequacy of this method for treatment of fractures in ankylosed cervical spine. METHODS: Prospectively collected clinical data, together with radiological documentation of a series of 8 consecutive patients with 9 cervical spine fracture were included in the analysis. The evaluation of screw insertion accuracy based on postoperative CT imaging, description of instrumentation-related complications and evaluation of morphological and clinical results were the subjects of interest. RESULTS: Of the 66 implants inserted in all cervical levels and in upper thoracic spine, only 3 screws (4.5%) did not meet the criteria of anatomically correct insertion. Neither screw malposition nor any other intraoperative events were complicated by any neural, vascular or visceral injury. Thus we did not find a reason to change implant position intraoperatively or during the postoperative period. The quality of intraoperative CT imaging in our group of patients was sufficient for reliable trajectory planning and implant insertion in all segments, irrespective of the habitus, positioning method and comorbidities. In addition to stabilization of the fracture, the posterior approach also allows reducing preoperative kyphotic position of the cervical spine. In all patients, we achieved a stable situation with complete bone fusion of the anterior part of the spinal column and lateral masses at one year follow-up. CONCLUSION: Spinal navigation based on intraoperative CT imaging has proven to be a reliable and safe method of stabilizing cervical spine with ankylosing spondylitis. The strategy of posterior stabilization seems to be a suitable method providing high primary stability and the conditions for a subsequent high fusion rate.

T2-relaxation time increases in lumbar intervertebral discs after 21d head-down tilt bed-rest.

OBJECTIVES: Spaceflight back pain and intervertebral disc (IVD) herniations cause problems in astronauts. Purpose of this study was to assess changes in T2-relaxation-time through MRI measurements before and after head-down tilt bed-rest, a spaceflight analog. METHODS: 8 men participated in the bed-rest study. Subjects remained in 6° head down tilt bed-rest in two campaigns of 21 days, and received a nutritional intervention (potassium bicarbonate 90 mmol/d) in a cross-over design. MRI measurements were performed 2 days before bed-rest, as well as one and five days after getting up. Image segmentation and data analysis were conducted for the IVDs Th12/L1 to L5/S1. RESULTS: 7 subjects, average age of 27.6 (SD 3.3) years, completed the study. Results showed a significant increase in T2-time in all IVDs (p⟨0.001), more pronounced in the nucleus pulposus than in the annulus fibrosus (p⟨0.001). Oral potassium bicarbonate did not show an effect (p=0.443). Pfirrmann-grade correlated with the T2-time (p⟨0.001). CONCLUSIONS: 6° head-down tilt bed-rest leads to a T2-time increase in lumbar IVDs. Oral potassium bicarbonate supplementation does not have an effect on IVD T2-time.

[Intraoperative CT-based spinal navigation: the initial 295 implants experience]. / Navigace v páterní chirurgii zalozená na intraoperacním CT zobrazení: zkusenost s iniciálními 295 implantáty.

INTRODUCTION: The authors describe the system of spinal navigation based on intraoperative CT imaging and the results of an initial series of patients. MATERIAL AND METHODS: Spinal screws inserted during 50 surgical procedures in the period between November 2012 and October 2013 were evaluated for insertion accuracy, intraoperative complications and the accessibility of the method for the selected spinal level. RESULTS: Out of the total of 295 screws inserted throughout all the spinal levels from C0 to S1, only 4 (1.3%) pedicle screws were found to be incorrectly inserted: a single L5 screw breached the lower cortex of the pedicle, two thoracic pedicular screws penetrated the anterior margin of the vertebral body not exceeding 3 mm of the shaft length, and a single C3 pedicle screw penetrated the upper vertebral body end-plate. None of these complications caused morbidity or required re-operation. Intraoperative CT imaging together with the navigation procedure increased the time of surgery by 30 minutes on average and patient radiation exposure during the initial and accuracy control CT scan was increased. CONCLUSION: Our initial experience has shown that the CT-based computer-assisted spinal navigation system is a precise surgical modality. It enables higher accuracy in spinal screw positioning, resulting in lower surgical morbidity and increased safety for the patient. This benefit should outweigh the longer operation time as well as a higher radiation exposure of the patients.

Microwave guiding of electrons on a chip.

We demonstrate the transverse confinement and guiding of a low energy electron beam of several electron volts in a miniaturized linear quadrupole guide. The guiding potential is generated by applying a microwave voltage to electrodes fabricated on a planar substrate, which allows the potential landscape to be precisely shaped on a microscopic scale. We realize transverse trapping frequencies of 100 MHz and guide electrons along a circular section of 37 mm length. A detailed characterization of the guiding properties in terms of potential depth and dynamic stability is given. This new technique of electron guiding promises various applications in guided matter-wave experiments such as electron interferometry.

[Surgical treatment of fracture of the ring of axis - "hangman's fracture"]. / Chirurgické resení fraktury oblouku epistrofeu - "katovské zlomeniny".

PURPOSE OF THE STUDY: To evaluate surgical management of the fracture of the ring of axis (FRA), known as "hangman's fracture", and to discuss adequacy of this treatment. MATERIAL AND METHODS: Between 1994 and 2004, 41 patients with FRA were surgically treated in our hospital. We present a retrospective study of 30 cases treated by anterior cervical fixation and fusion and 11 cases treated by a posterior, CT-guided approach (published recently). Our diagnostic algorithm for evaluation of FRA included plain radiographs for basic diagnosis, detailed CT scan, MRI and finally passive lateral flexion-extension fluoroscopy (performed by physician) to assess stability. We also consider discography in selected cases, allowing further evaluation of discoligamentous injury. Fractures were classified according to Levine. Posterior compressive osteosynthesis according to Judet was performed in 11 patients with Levine type I fractures with fracture fragment distraction > 3 mm. Anterior graft and plate fixation was chosen in 30 patients with type II (25 patients) and type I (5 patients) fractures where C2/3 disc injury was confirmed by MRI or discography. There was no case of facet dislocation in our series (type III). Pain, motion restriction and overall satisfaction with neck status were assessed on a scale 1-5 (1 = best) in patients treated with anterior approach. Self-evaluation questionnaires were administered during follow-up (average, 7.3 years; 24 months to 11 years). RESULTS: Anatomically reduced fracture fusion was achieved in all cases (100%) at one year follow-up. Both autologous tricortical (22) and fibular allografts (8) were used for anterior approach. No perioperative complications occurred and no case was aborted. Average hospital stay in patients with standalone FRA was 6.8 days (3-15). Patients wore Philadelphia collar for 4-6 weeks. One patient died during follow up due to unrelated causes. None of the 29 patients treated with the anterior approach reported severe or very severe pain (grades 4 or 5). The average pain score was 1.28. Three patients with isolated FRAs reported slight subjective restriction of movement (grade 2). The "satisfaction with overall neck status" scale showed an average score of 1.62, never worse than grade 2. DISCUSSION: Despite increasing popularity of anterior surgical approach in the treatment of type II FRA, most authors still recommend conservative treatment. Surgical treatment is consensually recommended in type III fractures only. Type I is treated exclusively conservatively. There is currently no evidence-based data supporting any method of treatment of so called "hangman's fracture". The majority of treating surgeons do not consider the status of the intervertebral disc. Dynamic films, simulating the peak point of injury, are usually not performed. Hence, potentially unstable fractures are overlooked. This also explains the lack of long term follow-up data regarding the radiological status of C2/3 intervertebral disc as well as patients' subjective complaints. CONCLUSIONS: Surgery provides plausible results. Compared to conservative treatment, it can offer significant benefits: 1) immediate, better and stable reposition; 2) high fusion rate; 3) shortening of the treatment period with better quality of life. Contrary to conservative treatment modalities, surgery possesses a potential for further development.

Mechanism of Fe(III)-Zn(II) purple acid phosphatase based on crystal structures.

Purple acid phosphatase is a widely distributed non-specific phosphomonoesterase. X-ray structures of the dimeric 111-kDa Fe(III)-Zn(II) kidney bean purple acid phosphatase (kbPAP) complexed with phosphate, the product of the reaction, and with tungstate, a strong inhibitor of the phosphatase activity, were determined at 2.7 and 3.0 angstroms resolution, respectively. Furthermore the resolution of the unligated enzyme, recently solved at 2.9 angstroms could be extended to 2.65 angstroms with completely new data. The binding of both oxoanions is not accompanied by larger conformational changes in the enzyme structure. Small movements with a maximal coordinate shift of 1 angstroms are only observed for the active site residues His295 and His296. In the inhibitor complex as well as in the product complex, the oxoanion binds in a bidentate bridging mode to the two metal ions, replacing two of the presumed solvent ligands present in the unligated enzyme form. As also proposed for the unligated structure a bridging hydroxide ion completes the coordination spheres of both metal ions to octahedral arrangements. All three structures reported herein support a mechanism of phosphate ester hydrolysis involving interaction of the substrate with Zn(II) followed by a nucleophilic attack on the phosphorus by an Fe(III)-coordinated hydroxide ion. The negative charge evolving at the pentacoordinated transition state is probably stabilized by interactions with the divalent zinc and the imidazole groups of His202, His295, and His296, the latter protonating the leaving alcohol group.

Crystallization and preliminary crystallographic data of purple acid phosphatase from red kidney bean.

Purple acid phosphatase from red kidney bean has been crystallized from ammonium sulfate solutions in the pH range from 3.5 to 5.5. The crystal form is tetragonal bipyramidal and the largest crystals grew up to 2.0 mm long. Systematic absences indicate one of the enantiomorphic space groups P4(1)2(1)2 (92) or P4(3)2(1)2 (96) with cell dimensions a = b = 104.1(1) A and c = 308.7(2) A. The asymmetric unit contains one dimer with Mr of 110,700, determined by ultraviolet-laser desorption mass spectrometry. The crystals, with a salt-free density of 1.12 g/cm3 and a water content of 67%, diffract to 3.5 A.

Coexistence of purino- and pyrimidinoceptors on activated rat microglial cells.

1. Nucleotide-induced currents in untreated (proliferating) and lipopolysaccharide (LPS; 100 ng ml(-1)) treated (non-proliferating) rat microglial cells were recorded by the whole-cell patch-clamp technique. Most experiments were carried out on non-proliferating microglial cells. ATP (100 nM-1 mM), ADP (10 nM-10 mM) and UTP (1 microM-100 mM), but not uridine (100 microM-10 mM) produced a slow outward current at a holding potential of 0 mV. The effect of UTP (1 mM) did not depend on the presence of extracellular Mg2+ (1 mM). The outward current response to UTP (1 mM) was similar in non-proliferating and proliferating microglia. 2. In non-proliferating microglial cells, the ATP (10 microM)-induced outward current was antagonized by suramin (300 microM) or reactive blue 2 (50 microM), whereas 8-(p-sulphophenyl)-theophylline (8-SPT; 100 microM) was inactive. By contrast, the current induced by UTP (1 mM) was increased by suramin (300 microM) and was not altered by reactive blue 2 (50 microM) or 8-SPT (100 microM). 3. The current response to UTP (1 mM) disappeared when K+ was replaced in the pipette solution by an equimolar concentration of Cs+ (150 mM). However, the effect of UTP (1 mM) did not change when most Cl- was replaced with an equimolar concentration of gluconate (145 mM). The application of 4-aminopyridine (1 mM) or Cs+ (1 mM) to the bath solution failed to alter the UTP (1 mM)-induced current. UTP (1 mM) had almost no effect in a nominally Ca2+-free bath medium, or in the presence of charybdotoxin (0.1 microM); the inclusion of U-73122 (5 microM) or heparin (5 mg ml(-1)) into the pipette solution also blocked the responses to UTP (1 mM). By contrast, the effect of ATP (10 microM) persisted under these conditions. 4. I-V relations were determined by delivering fast voltage ramps before and during the application of UTP (1 mM). In the presence of extracellular Cs+ (1 mM) and 4-aminopyridine (1 mM) the UTP-evoked current crossed the zero current level near -75 mV. Omission of Ca2+ from the Cs+ (1 mM)- and 4-aminopyridine (1 mM)-containing bath medium or replacement of K+ by Cs+ (150 mM) in the pipette solution abolished the UTP current. 5. Replacement of GTP (200 microM) by GDP-beta-S (200 microM) in the pipette solution abolished the current evoked by UTP (1 mM). 6. When the pipette solution contained Cs+ (150 mM) instead of K+ and in addition inositol 1,4,5,-trisphosphate (InsP3; 10 microM), an inward current absolutely dependent on extracellular Ca2+ was activated after the establishment of whole-cell recording conditions. This current had a typical delay, a rather slow time course and did not reverse its amplitude up to 100 mV, as measured by fast voltage ramps. 7. A rise of the internal free Ca2+ concentration from 0.01 to 0.5 microM on excised inside-out membrane patches produced single channel activity with a reversal potential of 0 mV in a symmetrical K+ solution. The reversal potential was shifted to negative values, when the extracellular K+ concentration was decreased from 144 to 32 mM. By contrast, a decrease of the extracellular Cl- concentration from 164 to 38 mM did not change the reversal potential. 8. Purine and pyrimidine nucleotides act at separate receptors in rat microglial cells. Pyrimidinoceptors activate via a G protein the enzyme phospholipase C with the subsequent release of InsP3. The depletion of the intracellular Ca2+ pool appears to initiate a capacitative entry of Ca+ from the extracellular space. This Ca2+ then activates a Ca2+-dependent K+ current.

An unsymmetrical tripodal ligand with an N2OS donor set: coordination chemistry with nickel(II)ions and aerial oxidation to the sulfinate complex

The synthesis of the previously unknown tripodal ligand H4-1 is reported. The tetradentate ligand is equipped with a completely unsymmetrical N2OS donor set. It reacts with Ni(OAc)2. 4H2O or Ni(ClO4)2.6H2O to give the multinuclear nickel(II) complexes [Ni(H-1-Imin)(OAc)]2 (2) (which contains a coordinated Schiff base obtained by reation of the primary amine with the acetone solvent) and [Ni3(H3-1)(H2-1)2]-ClO4.H2O.3 MeCN (3), respectively. A solution of 3 in DMF is readily oxidized upon exposure to air or by aqueous H2O2 to yield [Ni(H2-1-sulfinate)]2. 2MeOH (4). The molecular structures of 2-4 have been determined by X-ray diffraction. Complex 2 exhibits a strongly distorted, octahedral coordination geometry around each nickel(II)ion. The primary amino group of the ligand in this case reacted with the solvent acetone to yield a Schiff base which is coordinated to the metal center. The molecular structure of the trinuclear complex cation in 3 consists of two subunits: a nickel atom with a square-planar N2S2 coordination geometry and two other nickel atoms with a trigonal-bipyramidal N2O2S coordination environment. The dinuclear complex 4 shows distorted octahedral geometry around each nickel(II) ion. The thiolato groups of the ligands are oxidized to sulfinato groups which are O,O-bound to the nickel center. This coordination mode is unusual for nickel sulfinate complexes.

Base-induced heterochiral dimerization of an oxiranyl carbaldimine: stereoselective synthesis of a highly functionalized aziridine.

[reaction: see text] Treatment of the oxiranyl carbaldimine with base (LDA or LDA/KOtBu) leads in an one-step procedure to the polyfunctionalized aziridine. This highly diastereoselective reaction is explained by a new type of an Aza-Darzens reaction, in which one enantiomer of the starting material is deprotonated to form an oxiranyl anion, which attacks the imine carbon atom of the other enantiomer (mutual kinetic resolution by double diastereofacial selection).

Synthesis of enantiomerically enriched allenes by (-)-sparteine-mediated lithiation of alkynyl carbamates.

[reaction: see text]. The alpha-deprotonation of alkynyl carbamates 3 with the chiral base (-)-sparteine (4)/n-butyllithium, transmetalation with ClTi(O(i)()Pr)3, and subsequent substitution with an aldehyde results in the formation of enantioenriched 4-hydroxyallenyl carbamates 11. Stereoselection is determined by dynamic resolution of the lithium/(-)-sparteine complexes by selective crystallization.

On the chemical modification of pacemaker electrodes and patterned surface functionalization of planar substrates.

We report on experiments towards the chemical modification of metal electrodes in order to enhance biocompatibility or improve cell adhesion properties. In the first example pacemaker electrodes were modified with a thin polysiloxane network which allowed for further derivatization with a poly(ethylene glycol) layer. The primary goal was to suppress inflammatory response of tissue after implantation of electrodes. FTIR, ESCA and a.c.-impedance spectroscopy show the integrity of the ultrathin membrane. No significant reduction of the electrode capacitance was observed, providing further proof for the deposition of a homogeneously thin membrane. The second example deals with the patterned chemical modification of planar surfaces. The goal was to eventually effect selective adhesion of electrosensitive cells above microelectrodes for stimulation and/or recording. First results demonstrate the compatibility of monolayer deposition techniques with common photolithography. It is thus possible to create surfaces with patterned chemical functionality. A gas-phase silylation process was developed in order to control more precisely surface hydration and reaction parameters than is possible with common solution-based silylation procedures.

Pharmacological characterization of P2 purinoceptor types in rat locus coeruleus neurons.

The frequency of spontaneous action potentials of locus coeruleus neurons was recorded extracellularly in pontine slices of the rat brain. The adenosine 5'-triphosphate (ATP) analogues alpha,beta-methylene ATP (alpha,beta-meATP) and 2-methylthio ATP increased the firing rate with a similar potency, while uridine 5'-triphosphate (UTP) was inactive. Diadenosine 5'-pentaphosphate (Ap5A), diadenosine 5'-tetraphosphate (Ap4A) and diadenosine 5'-triphosphate (Ap3A) all facilitated the firing. When equimolar concentrations were compared, Ap5A had the largest effect followed by Ap4A and Ap3A. Suramin markedly inhibited responses to alpha,beta-meATP and 2-methylthio ATP; the effect of Ap4A was only slightly depressed by suramin. Pyridoxalphosphate-6-azophenyl-2,4-disulfonic acid (PPADS) strongly antagonized alpha, beta-meATP, but failed to alter the effects of 2-methylthio ATP and Ap4A. Reactive blue 2 weakly antagonized alpha,beta-meATP and did not interfere with 2-methylthio ATP and Ap4A. Moreover, suramin depressed responses to (S)-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and N-methyl-D-aspartic acid (NMDA), but not to substance P. PPADS failed to affect the AMPA- and NMDA-induced increases in firing. Hence, locus coeruleus neurons may possess receptors for adenosine nucleotides (P2X and P2Y purinoceptors) and dinucleotides (P2D purinoceptors); receptors for uridine nucleotides (P2U purinoceptors or pyrimidinoceptors) are probably absent.

Inhibition by ethanol of excitatory amino acid receptors and nicotinic acetylcholine receptors at rat locus coeruleus neurons.

The frequency of spontaneous action potentials of locus coeruleus (LC) neurons was recorded extracellularly in pontine slices of the rat brain. Ethanol (1-100 mM) elevated the firing rate in most neurons; this effect was concentration-dependent. (S)-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA; 0.03-1 microM), kainate (0.1-3 microM), N-methyl-D-aspartate (NMDA; 1-30 microM), substance P (0.01-1 microM), nicotine (0.1-10 microM) and alpha,beta-methylene ATP (alpha,beta-meATP; 0.3-30 microM), all increased the firing. Application of ethanol (10-100 mM) to the superfusion medium for 10 min, reproducibly and concentration-dependently inhibited the facilitatory effect of NMDA (10 microM). However, the inhibitory effect of ethanol (100 mM) decreased during a 30-min superfusion period and after the wash-out of ethanol the sensitivity of LC neurons to NMDA (10 microM) tended to overshoot above their initial level. Although NMDA was more potent in the absence than in the presence of external Mg2+, ethanol (100 mM) continued to depress the facilitatory effect of a low concentration of NMDA (3 microM) in a Mg(2+)-free medium. By contrast, in a medium containing normal Mg2+, ethanol (100 mM) failed to significantly interfere with the increase in firing rate induced by a high concentration of NMDA (30 microM). The effects of kainate (0.5 microM), AMPA (0.3 microM) and nicotine (1 microM) were also depressed by ethanol (100 mM), while the effects of substance P (0.03 microM) and alpha,beta-meATP (30 microM) were not changed.(ABSTRACT TRUNCATED AT 250 WORDS)

No evidence for functional imidazoline receptors on locus coeruleus neurons.

alpha 2-Adrenoceptor agonists inhibit the firing of locus coeruleus (LC) neurons. It was recently observed that the alpha-adrenoceptor agonists clonidine, rilmenidine and cirazoline, when injected intravenously in anaesthetized rats pretreated with the irreversible alpha 2-adrenoceptor antagonist N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ), excite the LC. The effect was attributed to activation of I1 imidazoline receptors. The aim of the present experiments was to characterize the direct effect of alpha 2-adrenoceptor and I1 imidazoline receptor agonists on LC neurons. Electrical activity of LC neurons was extracellularly recorded in midpontine slices prepared from the rat brain. Concentration-response curves were obtained for the alpha 2-agonist noradrenaline and the mixed I1/alpha 2-receptor agonists clonidine, rilmenidine and moxonidine in slices without treatment and in slices treated with 6-chloro-N-methyl-2,3,4,5-tetrahydro-1H-3-benzazepine (SK&F86466) or EEDQ, alpha 2-adrenoceptor antagonists with low affinity for I1 and I2 imidazoline receptors, respectively. All four agonists concentration-dependently reduced the firing rate of the neurons, with full inhibition at higher concentrations. SK&F86466 shifted the concentration-response curves of the agonists to the right; the calculated antagonist dissociation constants are compatible with an effect of the agonists on alpha 2-adrenoceptors. EEDQ completely prevented the inhibition by the agonists. Neither in SK&F86466- nor in EEDQ-treated slices was an excitation by clonidine, rilmenidine and moxonidine observed. We conclude that the LC neurons do not possess functional I1 (and also no I2) imidazoline receptors. The effects of noradrenaline, clonidine, rilmenidine and moxonidine on the neurons can be fully explained with an interaction with inhibitory alpha 2-adrenoceptors (probably of the alpha 2D subtype). The excitation of the LC by imidazoline receptor agonists under in vivo conditions, hence, is not a direct effect on the neurons of the LC.

Modulation of locus coeruleus neurons by extra- and intracellular adenosine 5'-triphosphate.

The cell membrane of rat locus coeruleus (LC) neurons is sensitive to both extra- and intracellular ATP. Extracellular ATP or its enzymatically stable analogues activate membrane receptors of the P2 type. These receptors inhibit a persistent potassium current and simultaneously activate a nonselective cationic conductance. The resulting depolarization increases the spontaneous firing rate. A decrease in the concentration of intracellular ATP during hypoxia or hypoglycemia opens ATP-sensitive K+ (KATP) channels of LC neurons. The resulting hyperpolarization depresses the discharge of action potentials and conserved energy. The hypoxia-induced hyperpolarization is additionally due to the release of adenosine from neighboring neurons or glial cells. A certain class of compounds, termed potassium channel openers, also decrease the firing, while sulphonylurea antidiabetics known to block KATP channels increase it. Sulphonylurea antidiabetics antagonize the excitability decrease induced both by potassium channel openers and metabolic damage.

Percutaneous fixation of three- and four-part fractures of the proximal humerus.

Untreated 3- and 4-part fractures of the proximal humerus have a poor functional outcome. Open operation increases the risk of avascular necrosis and percutaneous reduction and fixation may be preferable. We report 27 patients, 9 with 3-part and 18 with 4-part fractures, treated by percutaneous reduction and screw fixation. Thirteen of the 4-part fractures were of the valgus type with no significant lateral displacement of the articular segment, and five showed significant shift. Instruments were introduced into the fracture through small incisions so that the fragments could be manoeuvred under the control of an image intensifier, taking advantage of ligamentotaxis as far as possible. A good reduction was achieved in most cases. The average follow-up was 24 months (18 to 47). All the 3-part fractures showed good to very good functional results, with an average Constant score of 91% (84% to 100%), and no signs of avascular necrosis. Good radiological results were achieved in 4-part fractures when impacted in valgus except for one patient with partial avascular necrosis of the head. In those with lateral displacement of the head, revision to a prosthesis was required in one patient because of avascular necrosis and in another because of secondary redisplacement of the fracture. Avascular necrosis was seen in 11% of 4-part fractures. The average Constant score in patients with 4-part fractures who did not need further operation was 87% (75% to 100%).

Experimental transfer of Trichomonas gallinae (Rivolta, 1878) from white-winged doves to mourning doves.

Isolates of Trichomonas gallinae (Rivolta, 1878) from white-winged doves, Zenaida asiatica (L.), were transferred experimentally to young mourning doves, Zenaida macroura (L.). Twenty-three of 25 mourning doves developed infections with isolates of T. gallinae from 25 white-winged doves. In addition, eight of eight rock doves (Columba livia Gmelin) were infected with duplicate isolates. All infected recipient birds harbored avirulent isolates except for one mourning dove which died from extensive oral lesions. However, repeated attempts using this isolate of T. gallinae to produce lesions in additional recipients were unsuccessful. Despite the findings of this study, it was suggested that future dove management strategies consider the possibility of disease outbreaks involving white-winged doves and susceptible populations of mourning doves.

[Racemate resolution by MBF-lactol as a protecting group--a "modified" MBF-lactol]. / Racematspaltung mit MBF-Lactol als Schutzgruppe--Auffinden eines "modifizierten" MBF-Lactols.

For the resolution of racemic 2 MBF-Lactol (3) was used. After 40 h an excess of 3 gave a new product, the "modified" MBF-Lactol 6. This has a high enantiomeric selectivity and leads to well crystallized derivatives.