Hybrid total hip arthroplasty for multiple epiphyseal dysplasia

BACKGROUND

Multiple Ephiphyseal Dysplasia (MED) is a rare autosomal dominant skeletal dysplasia that causes deformation of the epiphysis of the involved joints. The hips are invariably affected and symptoms due to incapacitating early onset degenerative hip disease often begin between the second and fourth decade of life. Literature regarding the clinical and radiographical outcomes after total hip arthroplasty in this young population are very scarce. Hypothesis in patients with multiple epiphyseal dysplasia and early onset degenerative hip disease, hybrid total hip arthroplasty is a safe and reliable procedure.

PATIENTS AND METHODS

We followed 10 hybrid total hip arthroplasties in 6 patients with respect to the early and medium term complications. The average age at surgery was 32 years old (17 to 41). All stems were cemented polished straight tapered stems, all cups were porous coated uncemented cups. The mean duration of follow-up was 10.3 (7-14, SD2.8) years. Clinical outcomes were measured using the Charnley modification of the Merle d'Aubigné-Postel grading system and VAS-scores.

RESULTS

No early complications and no revisions occurred and patients significantly improved for pain, function and mobility. The Charnley, Merle d'Aubigné and Postel hip scores significantly improved from 9.6 points pre-operatively (range: 8-11 points) to 17 points (range: 16-18 points) and the VAS-score significantly improved after surgery from respectively 7 at rest and 8.5 during activity preoperatively to 1 at rest and 1.5 during activity postoperatively. Radiographic evaluation showed no cases of radiolucency around the cemented femoral components. No migration or subsidence of the components was noted. With regard to the acetabular component, osteolysis was noted in 4 hips, but serial radiographs showed no progression or migration of the component and the patients were completely pain free.

CONCLUSION

Hybrid total hip arthroplasty is a viable treatment option in multiple epiphyseal dysplasia patients, with excellent mid-term clinical and radiographical outcomes.

LEVEL OF EVIDENCE

Level IV, retrospective study.

Restless legs syndrome associated with exercise intolerance: Data from a retrospective observational clinical neuromuscular center study

INTRODUCTION

Exercise intolerance (EI) is a frequent motive for seeking neuromuscular consultation and may be a sign of metabolic disease or, rarely, muscular dystrophy. The diagnosis is not established in many patients with a typical clinical presentation. Nevertheless, some of them complain of sleep disorders and more especially of restless legs syndrome (RLS).

OBJECTIVE

The objective of our study was to estimate the frequency of RLS in patients presenting with EI.

METHODS

Our retrospective observational study included all patients seen in the center from 2005 to 2011, who were subsequently investigated for EI in the neuromuscular department of the Caen University hospital. Data were collected on clinical RLS and muscular investigations (creatine kinase [CK], EMG, maximal exercise tests magnetic resonance imaging [MRI] and muscle biopsy obtained along with muscle exploration).

RESULTS

Of the 318 patient records analyzed, 84 showed patients accurately complaining of EI. RLS was diagnosed in 25 of these patients (29.7%). This percentage was significantly higher (P<0.001) than found in the general population. Improvement was seen in 91.3% of the patients receiving specific treatment.

CONCLUSION

RLS can sometimes present with pain, potentially worsening with exercise, inappropriately leading to a hypothesis of EI. Clinicians should thus explore the possible diagnosis of RLS when a muscular disease is not found in patients presenting with such symptoms.

Hip resurfacing arthroplasty: current status and future perspectives

Hip resurfacing arthroplasty (HRA) is a concept of hip replacement that allows treating young active patients with a femoral bone preserving procedure. The proposed advantages of resuming an active lifestyle with increased frequency and duration of sports activities have been shown to be realistic. The 30-year cost-effectiveness in young male patients has been shown to be higher in resurfacing compared to conventional total hip replacement (THA). However, prognosticators of an inferior outcome have also been identified. The most important patient related factors are secondary osteoarthritis as the indication for surgery such as post-childhood hip disorders or AVN, female gender, smaller component sizes and older age (>65 years for males and >55 years for females). In addition, surgical technique (approach and cementing technique) and component design are also important determinant factors for the risk of failure. Moreover, concerns have surfaced with respect to high metal ion concentrations and metal ion hypersensitivities. In addition, the presumed ease of revising HRA has not reflected in improved or equal survivorship in comparison to a primary THA. This highlights the importance of identifying patient-, surgery-, and implant-related prognosticators for success or failure of HRA. Rather than vilifying the concept of hip resurfacing, detailed in depth analysis should be used to specify indications and improve implant design and surgical techniques.

Production, formulation and antagonistic activity of the biocontrol like-yeast Aureobasidium pullulans against Penicillium expansum

Aureobasidium pullulans (de Bary) Arnaud (Ach 1-1) was grown in a glucose fed-batch fermentor to 106 g dry wt l(-1) in 48 h. The cells were dried in a fluidized bed dryer with a final viability of 62%. After 7 months at 4 degrees C, the viability was 28% of the initial value (= 2.3 x 10(10 )c.f.u. g(-1) dry matter). A protection level of 89% was achieved with the biomass preparation at 1 x 10(8 )c.f.u. ml(-1) after 28 and 7 days for apples stored respectively at 5 and 25 degrees C against Penicillium expansum. Our process is suitable to produce large quantities of the strain Ach 1-1 as biological control agent for apple preservation.

Recovery of nuclease produced by Lactococcus lactis using expanded bed ion exchange chromatography

Expanded bed-ionic exchange chromatography (EB-IEC) was used for the recovery and purification of recombinant staphylococcal nuclease secreted by Lactococcus lactis. At the end of the fermentation process, the nuclease activity reached 39 U ml(-1). The EB-IEC performances were firstly evaluated with clarified culture broth. The isocratic elution with 0.5 M NaCl led to approximately 80% of nuclease recovery. Proceeding with 3-fold bed expansion resulted in a reduction of the resin capacity by a factor of 32% compared to the process in a packed bed configuration. Simplification of the early purification steps was reached by loading immediately the unclarified culture broth previously diluted to reduce conductivity. Presence of Cells did not affect the chromatography performances resulting in 55-fold purification with the same yield.

A semi-active milling procedure in view of preparing implantation beds in robot-assisted orthopaedic surgery

Bone cutting in total joint reconstructions requires a high accuracy to obtain a well-functioning and long-lasting prosthesis. Hence robot assistance can be useful to increase the precision of the surgical actions. A drawback of current robot systems is that they autonomously machine the bone, in that way ignoring the surgeon's experience and introducing a safety risk. This paper presents a semi-active milling procedure to overcome that drawback. In this procedure the surgeon controls robot motion by exerting forces on a force-controlled lever that is attached to the robot end effector. Meanwhile the robot constrains tool motion to the planned motion and generates a tool feed determined by the feed force that the surgeon executes. As a case study the presented milling procedure has been implemented on a laboratory set-up for robot-assisted preparation of the acetabulum in total hip arthroplasty. Two machining methods have been considered. In the first method the surgeon determines both milling trajectory and feed by the forces that he/she executes on the force-controlled lever. In the second method the cavity is machined contour by contour, and the surgeon only provides the feed. Machining experiments have shown that the first method results in large surface irregularities and is not useful. The second method, however, results in accurate cavity preparation and has therefore potential to be implemented in future robot systems.

Posterior transosseous capsulotendinous repair in total hip arthroplasty : a cadaver study

BACKGROUND

While recent clinical articles have reported a dramatic reduction in rates of total hip dislocation after posterior transosseous repair, we are not aware of any published biomechanical data to support this finding. The objectives of this study were to investigate the functional anatomy of the posterior transosseous repair and its effect on stability after total hip replacement.

METHODS

Six total hip prostheses were implanted into three fresh cadavera. Three different repair situations (no repair, soft-tissue repair, and transosseous fixation) were then consecutively tested on each hip. Values for torque resistance and the angular range of motion at dislocation were recorded. Each repair was tested twice, yielding a total of thirty-six torque values and thirty-six angles of rotation.

RESULTS

The transosseous repair was superior with regard to both torsion strength (four times stronger than that after no repair [p = 0.0002] and more than twice as strong as that after soft-tissue repair [p = 0.002]) and the magnitude of the angle of rotation observed prior to dislocation (an increase of 83% in comparison with that after no repair [p = 0.0005] and an increase of 46% in comparison with that after soft-tissue repair [p = 0.004]).

CONCLUSIONS

In a cadaver model, posterior transosseous repair provides superior stability of a total hip replacement. Optimal surgical technique with a slightly modified approach allows greater retention of capsule and tendon length and a more anatomical reinsertion of the soft tissues.

One-stage bilateral total hip replacement: a retrospective study of 70 patients

In this study, we retrospectively reviewed 70 patients who had a one-stage bilateral total hip replacement in our institution, between 1992 and 1998. Different variables were considered such as gender, age, length of hospital stay, pre-operative diagnosis, duration of the operation and anesthesia, type of prosthesis, complications and amount of blood loss, pre- and postoperative range of motion, incidence of periarticular heterotopic ossifications and postoperative pain and walking distance. In our group of patients one-stage bilateral total hip replacement was found to have resulted in good objective results. Patients with a rheumatoid condition had the highest gain in postoperative hip mobility. In comparison with existing literature there were no more intra- or postoperative complications, making one-stage bilateral total hip replacement a safe procedure in well-selected cases.

Parsonage-Turner syndrome after total-hip arthroplasty

A 68-year-old patient developed Parsonage-Turner syndrome after total hip arthroplasty. There was an acute onset of intense pain in the shoulder 48 hours after surgery followed by complete paralysis of the shoulder and almost complete loss of strength in the arm. Recovery was slow, and mild weakness persisted 7 years after the operation. Parsonage-Turner syndrome has been associated with various surgical procedures but has not been reported after total hip arthroplasty. For medicolegal reasons, it should be distinguished from a traction injury of the brachial plexus or compression of the radial or ulnar nerve resulting from positioning of the patient. Parsonage-Turner syndrome should be considered in the differential diagnosis when a patient describes pain or weakness in the shoulder after joint arthroplasty.

Bifocal pubic stress fracture after ipsilateral total knee arthroplasty in rheumatoid arthritis. A case report

We present the case of a 78-year-old rheumatoid patient with a bifocal stress fracture of the pubic rami after ipsilateral total knee arthroplasty. Many risk factors that may cause insufficiency fractures are combined in rheumatoid arthritis. These patients are used to chronic pain, and therefore the diagnosis is often made late. When a patient suffering from rheumatoid arthritis presents with recent pain in the pelvic or hip region after hip or knee arthroplasty, a stress fracture should always be suspected. A standard pelvic radiograph and skeletal scintigraphy establish the diagnosis. CT-scan may be useful in the differential diagnosis with less benign pathology. Rest and analgesic drugs are sufficient to let the fracture heal. Nonunion has never been reported for these fractures.

Functional role of transmembrane helix 7 in the activation of the heptahelical lutropin receptor

A member of the G protein-coupled receptor superfamily, the LH receptor (LHR), and the two other glycoprotein hormone receptors are distinguished from the other members by the presence of a relatively large N-terminal extracellular domain that is responsible for high-affinity ligand binding. Transmembrane helix (TMH) 7 of LHR is amphipathic, with an extended face containing only hydrophobic side chains and another containing both hydrophobic and polar side chains with potential hydrogen bond donor and acceptor functions. Since several reports have shown the importance of this helix in ligand-mediated signaling, we have used Ala scanning mutagenesis to study eight amino acid residues of rat LHR that are invariant in the three glycoprotein hormone receptors, Leu586, Val587, Asn593, Ser594, Cys595, Asn597, Phe604, and Thr605. The wild type (WT) and mutant cDNAs were transiently transfected into COS-7 cells for characterization by human CG (hCG) binding and cAMP production. No differences were detected in dissociation constants (K(d)S) or basal cAMP production relative to WT LHR, but three categories of LHR mutants were distinguished from WT LHR based upon their expression levels and responsiveness to hCG: 1) comparable or higher expression but reduced ligand responsiveness (N593A and C595A), 2) reduced expression and ligand responsiveness (N597A and T605A), and 3) comparable expression and responsiveness (L586A, V587A, S594A, and F604A). Three other mutants, C595M, F604Y, and T605Y, were comparable to WT LHR in ligand responsiveness. To provide more information on Asn593 and Asn597, a total of 12 replacements were investigated. Of considerable interest and potential significance was the finding that many of the replacements in LHR resulted in either loss of function (N593A, Q, S; N597R) or gain of function (N593R and N597Q), this being the first evidence of a position in LHR that, depending upon the nature of the amino acid residue, can result in constitutive activation and/or diminished responsiveness to ligand. The results of molecular modeling and energy minimization of TMHs 6 and 7, based on a postulated interaction between Asp556 (TMH 6) and Asn593/Asn597 (TMH 7), indicated that, while there is not a correlation between function and predicted energies of WT LHR and the mutants, reorientation of one or both helices is responsible for the functional changes observed. Possible interactions of TMHs 3 and 4 and of 5 and 6 were suggested by molecular modeling. Ten mutants were prepared of two amino acid residues that are invariant in the glycoprotein hormone receptors and have side chain hydrogen bond donor and acceptor function, Glu429 in TMH 3 and Asn513 in TMH 5. Expression levels and hCG-mediated signaling were reduced in most of the LHR mutants, but none of these exhibited constitutive receptor activation. We conclude that Glu429 is not critical for receptor function, while Asn513 appears to be particularly important in receptor folding and/or trafficking. The results reported herein indicate an important role for TMH 7, and particularly Asn593 and Asn597, in the process of receptor activation. Moreover, these two asparagines, although in close proximity to each other in TMH 7, are quite distinct in function as evidenced by certain replacements that can lead to loss of function in one and gain of function in the other.

In vitro generation from the trans-Golgi network of coatomer-coated vesicles containing sialylated vesicular stomatitis virus-G protein

We describe an in vitro system in which post-Golgi vesicles containing metabolically labeled, sialylated, vesicular stomatitis virus (VSV) G protein molecules (VSV-G) are produced from the trans-Golgi network (TGN) of an isolated Golgi membrane fraction. This fraction is prepared from VSV-infected Madin-Darby canine kidney (MDCK) cells in which the (35)S-labeled viral envelope glycoprotein was allowed to accumulate in the trans-Golgi network during a prolonged incubation at 20 degrees C. The vesicles produced in this system are separated from the remnant Golgi membranes by differential centrifugation or by velocity sedimentation in a sucrose gradient. Vesicle production, quantified as the percentage of labeled VSV-G released from the Golgi membranes, is optimal at 37 degrees C and does not occur below 20 degrees C. It requires GTP and the small GTP-binding protein Arf (ADP-ribosylation factor), as well as coat protein type I (COPI) coat components (coatomer) and vesicle scission factors-one of which corresponds to the phosphatidylinositol transfer protein (PITP). Formation of the vesicles does not require GTP hydrolysis which, however, is necessary for their uncoating. Thus, vesicles generated in the presence of the nonhydrolyzable GTP analogs, GTPgammaS or GMP-PNP, retain a coatomer coat visible in the electron microscope, sediment more rapidly in sucrose density gradients than those generated with ATP or GTP, and can be captured with anticoatomerantibodies. The process of coatomer-coated vesicle formation from the TGN can be dissected into two distinct sequential phases, corresponding to coat assembly/bud formation and vesicle scission. The first phase is completed when Golgi fractions are incubated with cytosolic proteins and nonhydrolyzable GTP analogs at 20 degrees C. The scission phase, which leads to vesicle release, takes place when coated Golgi membranes, recovered after phase I, are incubated at higher temperatures in the presence of cytosolic proteins. The scission phase does not take place if protein kinase C inhibitors are added during the first phase, even though these inhibitors do not prevent membrane coating and bud formation. The phosphorylating activity of a protein kinase C, however, plays no role in vesicle formation, since this process does not require ATP.

Identification of a new Pyk2 target protein with Arf-GAP activity

Protein tyrosine kinase Pyk2 is activated by a variety of G-protein-coupled receptors and by extracellular signals that elevate intracellular Ca2+ concentration. We have identified a new Pyk2 binding protein designated Pap. Pap is a multidomain protein composed of an N-terminal alpha-helical region with a coiled-coil motif, followed by a pleckstrin homology domain, an Arf-GAP domain, an ankyrin homology region, a proline-rich region, and a C-terminal SH3 domain. We demonstrate that Pap forms a stable complex with Pyk2 and that activation of Pyk2 leads to tyrosine phosphorylation of Pap in living cells. Immunofluorescence experiments demonstrate that Pap is localized in the Golgi apparatus and at the plasma membrane, where it is colocalized with Pyk2. In addition, in vitro recombinant Pap exhibits strong GTPase-activating protein (GAP) activity towards the small GTPases Arf1 and Arf5 and weak activity towards Arf6. Addition of recombinant Pap protein to Golgi preparations prevented Arf-dependent generation of post-Golgi vesicles in vitro. Moreover, overexpression of Pap in cultured cells reduced the constitutive secretion of a marker protein. We propose that Pap functions as a GAP for Arf and that Pyk2 may be involved in regulation of vesicular transport through its interaction with Pap.

Coherent small-angle scattering on a bending-magnet beamline at the ESRF

A coherent X-ray beam is obtained from the D2AM bending-magnet beamline (BM2) of the European Synchrotron Radiation Facility. As this line has permanent convergent optics, monochromated by an Si(111) double monochromator, coherence conditions are satisfied by selecting a part of the beam close to the focal point. Low intensity (10(6) X-rays s(-1)) is partially compensated by a high degree of coherence and by the use of a high-resolution direct-illumination CCD area detector. The stability of the small-angle set-up makes quantitative analysis possible. The calculated and measured degrees of coherence are compared. The distributions of speckle intensities are explained by a beam composed of two-thirds coherent and one-third incoherent parts. This incoherent component is caused by Kapton windows, which will be removed in future experiments.

D2AM, a beamline with a high-intensity point-focusing fixed-exit monochromator for multiwavelength anomalous diffraction experiments

D2AM is a french CRG beamline installed at the ESRF (European Synchrotron Radiation Facility) in Grenoble, with half of the time dedicated to biological macromolecule crystallography and half to materials science studies (diffraction, wide-angle and small-angle scattering). It is constructed at the front-end BM02 of the ESRF storage ring, using the X-ray beam from a 0.8 T bending magnet. D2AM entered into routine operation at the end of 1994, and is used either for single-wavelength or for multiwavelength anomalous diffraction studies. The beam is monochromated by an Si[111] two-crystal monochromator with a resolution of about 2 x 10(-4). The first crystal is water cooled. The X-ray photon energy covers the range between 6.5 keV (lambda approximately 1.9 A) and 17 keV (lambda approximately 0.7 A), a domain of energy with many K or L absorption edges of heavy atoms of interest for biological macromolecules studies and in materials science. The X-ray beam is focused in the vertical plane by two long curved mirrors and in the horizontal plane by the second crystal of the monochromator which is given an adjustable sagittal curvature. A spot size of 0.3 x 0.1 mm (FWHM) is measured at the sample position. Both mirrors are cut out of a 6"-diameter 1.1 m-long Si single crystal, polished and coated with a 400 A Pt thin film. The rugosity is better than 4 A r.m.s. and the longitudinal slope error is better than 5 x 10(-6) rad r.m.s. The first mirror is water cooled, the second is not. The beam intensity on the sample is about 10(11) photon s(-1) on a 0.3 x 0.3 mm focus area at 100 mA in the storage ring of the ESRF. The harmonic rejection ratio obtained with the two mirrors is better than 10(-5) for lambda/3. The combined optical system, mirror/monochromating-crystals/mirror, used on D2AM constitutes altogether a high-intensity point-focusing fixed-exit monochromator, which has the additional property that the energy resolution is not dependent on the beam divergence in use. Its stability and resolution are perfectly adapted to multiwavelength anomalous diffraction studies. The alignment of the mirrors and the monochromator is fully automated, taking 5 min, with the exception of the adjustment of the sagittal focusing. During multiwavelength diffraction experiments the wavelength is changed by a fast single monochromator rotation. Neither realignment of the mirrors nor readjustment of the beam focusing are necessary. The stability and reproducibility of the selected X-ray photon energy is better than 0.5 eV.

An essential role for the phosphatidylinositol transfer protein in the scission of coatomer-coated vesicles from the trans-Golgi network

We identified the phosphatidylinositol transfer protein (PITP) as being responsible for a powerful latent, nucleotide-independent, Golgi-vesiculating activity that is present in the cytosol but is only manifested as an uncontrolled activity in a cytosolic protein subfraction, in which it is separated from regulatory components that appear to normally limit its action to the scission of COPI-coated buds from trans-Golgi network membranes. A specific anti-PITP antibody that recognizes the two mammalian PITP isoforms fully inhibited the capacity of the cytosol to support normal vesicle generation as well as the uncontrolled vesiculating activity manifested by the cytosolic protein subfraction. The phosphatidylinositol- (PI) loaded form of the yeast PITP, Sec14p, but not the phosphatidylcholine- (PC) loaded form of the protein, was capable of substituting for the cytosolic subfraction in promoting the scission of coated buds from the trans-Golgi network. At higher concentration, however, Sec14p, when loaded with PI, but not with PC or phosphatidylglycerol, caused by itself an indiscriminate vesiculation of uncoated Golgi membranes that could be suppressed by PC-Sec14p, which also suppresses the uncontrolled vesiculation caused by the cytosolic subfraction. We propose that, by delivering PI to specific sites in the Golgi membrane near the necks of coated buds, PITP induces local changes in the organization of the lipid bilayer, possibly involving PI metabolites, that triggers the fusion of the ectoplasmic faces of the Golgi membrane necessary for the scission of COPI-coated vesicles.

Core decompression for avascular necrosis of the femoral head

The results of core decompression as the sole treatment for Ficat stages 1, 2 and 3 avascular necrosis of 51 femoral heads in 39 patients were studied. The mean follow-up time was 24 months (6-47 months); 19 hips (38.8%) were good and 30 hips (61.2%) had failed (two hips were lost to follow-up). The good results as stated in the literature could not be obtained, but we believe core decompression can delay the need for total hip replacement in avascular necrosis of the femoral head.

Ganglia of the superior tibiofibular joint: report of three cases and review of the literature

Ganglion cysts that compress the common peroneal nerve frequently arise from the proximal tibiofibular joint. We report three cases of such ganglia. In one case the ganglion cyst arises from the proximal tibiofibular joint, finds its course along the common peroneal nerve causing pain, but no neurological deficit. In the two other cases the cysts have the same origin but they are the cause of a progressive peroneal nerve palsy. Treatment in these three cases was successful resection of the cyst with non mutilating surgery for the nerve and ligation of the stalk connecting the ganglion to the proximal tibiofibular articulation. A review of the controversial pathogenesis of the intra- and extraneural ganglia is exposed, and the anatomy, the diagnosis, the surgical treatment and the prognosis is discussed in light of relevant literature.

[Primary adrenal lymphoma with latent adrenal insufficiency: a case report and literature review]

We report a new case of primary adrenal lymphoma with latent adrenal insufficiency and long-term remission after hydrocortisone replacement therapy. We have analyzed 29 other cases described in the literature. This disease with poor prognosis can be revealed by an incidentally discovered, frequently bilateral, adrenal mass. Adrenal insufficiency may be latent and the diagnostic procedure should include both cortisol and ACTH determination with an additional ACTH stimulation test if appropriate. Early adrenal substitution can improve patient survival.

Coatomer, but not P200/myosin II, is required for the in vitro formation of trans-Golgi network-derived vesicles containing the envelope glycoprotein of vesicular stomatitis virus

Using a cytosol and nucleotide dependent assay that we previously developed, we have investigated the requirement for coat proteins in the in vitro production of trans-Golgi network (TGN)-derived vesicles from a Madin-Darby canine kidney (MDCK) cell Golgi fraction that contains the 35S-labeled, terminally glycosylated, envelope glycoprotein of vesicular stomatitis virus (VSV-G) accumulated in the TGN. We found that the TGN-derived vesicles, like those involved in intra-Golgi transport and in retrograde transport to the endoplasmic reticulum, contain a coatomer coat and that coatomer is required for their formation. Thus, after they are produced with GTPgammaS, the coated vesicles could be captured on beads containing anticoatomer antibody. Moreover, a cytosolic protein fraction depleted of coatomer could not support vesicle formation but it did so after purified coatomer was added. We also determined that P200/myosin II does not play an essential role in the in vitro generation of TGN-derived vesicles. Thus, removal of this protein from the cytosol, by differential salt precipitation or binding to phalloidin-induced actin filaments, had no effect on vesicle generation. Nevertheless, immunodepletion of cytosol using the anti-P200/myosin II AD7 antibody abolished vesicle generation and that antibody was capable of effectively immunocapturing coated vesicles, even when these were generated in the absence of P200/myosin II. These effects, however, are explained by the unexpected finding that the AD7 antibody interacts with undenatured coatomer.

Detection and partial characterization of a bacteriocin produced by Carnobacterium piscicola 213

BLIS 213, is a bacteriocin-like inhibitory substance produced by Carnobacterium piscicola 213. It is active against Carnobacterium, Enterococcus and Listeria spp. No activity was observed against tested Lactobacillus, Lactococcus, Leuconostoc and Pediococcus strains, nor against Gram-negative bacteria. The BLIS 213 activity was inactivated by several proteolytic enzymes. It was heat resistant (121 degrees C for 20 min), and stable over a pH range of 2-8. Activity was determined by a dilution micromethod; it was increased after SDS treatment. A mutant strain which lacks bacteriocin production was isolated and designated as Carnobacterium piscicola 213a. It had the same phenotypic and biochemical properties as the parent strain, and was not sensitive to bacteriocin activity. The apparent molecular weight of the bacteriocin in the crude extract was greater than 10 kDa. It was about 6 kDa after SDS-PAGE of a partially purified bacteriocin by adsorption on producer cells. The isoelectric point of the BLIS 213 was around 9.3.

Wear of a titanium-alloy shoulder prosthetic head

We present a case report of extensive wear that occurred on the surface of the titanium-alloy head of a shoulder prosthesis after only 2 years' service. Such wear warrants discontinuing the use of titanium-alloy articulating surfaces even in nonweight-bearing joints.

Mechanism of formation of post Golgi vesicles from TGN membranes: Arf-dependent coat assembly and PKC-regulated vesicle scission

We have developed an experimental system that utilizes purified Golgi fractions obtained from virus infected infected MDCK cells to reproduce in vitro the process of vesicle generation in the trans Golgi network, an important site for the sorting of proteins addressed to the plasma membrane, secretory vesicles, or lysosomes. Using an integrated biochemical and electron microscopic approach, we have shown that the formation of post Golgi vesicles carrying proteins destined to both plasma membrane domains of epithelial cells requires the activation of an ArF-like GTP-binding protein that serves to promote the assembly of the protein coat necessary to deform the donor membrane and generate a vesicle. The formation of the post Golgi vesicles also requires the participation of a Golgi membrane-associated Protein Kinase C, but not its phosphorylating activity. Other authors have shown that this is also the case for the PKC activation of the enzyme phospholipase D, which generates phosphatidic acid from phosphatidyl choline and may be involved in remodeling of membranes. We have been able to dissect the process of post Golgi vesicle generation into two sequential stages, one of coat assembly and bud formation, and a subsequent one of vesicle scission. The first stage can occur at 20 degrees C and requires the activation of the Arf protein necessary for coat assembly. The second stage does not require nucleotides or an energy supply, but requires cytosolic proteins, and in particular, an NEM sensitive membrane scission promoting activity that operates only at a higher temperature of incubation. Because various PKC inhibitors blocked vesicle scission without preventing bud formation, we propose that the PKC is required for the activation of a PLD in the TGN, which leads to remodeling of the donor membrane and the severing of connections between the emerging vesicles and the membranes.

The production of post-Golgi vesicles requires a protein kinase C-like molecule, but not its phosphorylating activity

We have recently described a system that recreates in vitro the generation of post-Golgi vesicles from purified Golgi fractions obtained from virus-infected MDCK cells in which the vesicular stomatitis virus-G envelope glycoprotein had been allowed to accumulate in vivo in the TGN. Vesicle formation, monitored by the release of the viral glycoprotein, was shown to require the activation of a GTP-binding ADP ribosylation factor (ARF) protein that promotes the assembly of a vesicle coat in the TGN, and to be regulated by a Golgi-associated protein kinase C (PKC)-like activity. We have now been able to dissect the process of post-Golgi vesicle generation into two sequential stages, one of coat assembly and bud formation, and another of vesicle scission, neither of which requires an ATP supply. The first stage can occur at 20 degrees C, and includes the GTP-dependent activation of the ARF protein, which can be effected by the nonhydrolyzable nucleotide analogue GTP gamma S, whereas the second stage is nucleotide independent and can only occur at a higher temperature of incubation. Cytosolic proteins are required for the vesicle scission step and they cannot be replaced by palmitoyl CoA, which is known to promote, by itself, scission of the coatomer-coated vesicles that mediate intra-Golgi transport. We have found that PKC inhibitors prevented vesicle generation, even when this was sustained by GTP gamma S and ATP levels reduced far below the K(m) of PKC. The inhibitors suppressed vesicle scission without preventing coat assembly, yet to exert their effect, they had to be added before coat assembly took place. This indicates that a target of the putative PKC is activated during the bud assembly stage of vesicle formation, but only acts during the phase of vesicle release. The behavior of the PKC target during vesicle formation resembles that of phospholipase D (PLD), a Golgi-associated enzyme that has been shown to be activated by PKC, even in the absence of the latter's phosphorylating activity. We therefore propose that during coat assembly, PKC activates a PLD that, during the incubation at 37 degrees C, promotes vesicle scission by remodeling the phospholipid bilayer and severing connections between the vesicles and the donor membrane.

The in vitro generation of post-Golgi vesicles carrying viral envelope glycoproteins requires an ARF-like GTP-binding protein and a protein kinase C associated with the Golgi apparatus

We have developed a system that recreates in vitro the generation of post-Golgi vesicles from an isolated Golgi fraction prepared from vesicular stomatitis virus- or influenza virus-infected Madin-Darby canine kidney or HepG2 cells. In this system, vesicle generation is temperature- and ATP-dependent and requires a supply of cytosolic proteins, including an N-ethylmaleimide-sensitive factor distinct from NSF. Cytosolic proteins obtained from yeast were as effective as mammalian cytosolic proteins in supporting vesicle formation and had the same requirements. The vesicles produced (50-80 nm in diameter) are depleted of the trans Golgi marker sialyltransferase, contain the viral glycoprotein molecules with their cytoplasmic tails exposed, and do not show an easily recognizable protein coat. Vesicle generation was inhibited by brefeldin A, which indicates that it requires the activation of an Arf-like GTP-binding protein that promotes assembly of a vesicle coat. Vesicles formed in the presence of the nonhydrolyzable GTP analogue guanosine 5'-3-O-(thio)triphosphate retained a nonclathrin protein coat resembling that of COP-coated vesicles, and sedimented more rapidly in a sucrose gradient than the uncoated ones generated in its absence. This indicates that GTP hydrolysis is not required for vesicle generation but that it is for vesicle uncoating. The activity of a Golgi-associated protein kinase C (PKC) was found to be necessary for the release of post-Golgi vesicles, as indicated by the capacity of a variety of inhibitors and antibodies to PKC to suppress it, as well as by the stimulatory effect of the PKC activator 12-O-tetradecanoylphorbol-13-acetate.

Influence of cigarette smoking on rate of reopening of the infarct-related coronary artery after myocardial infarction: a multivariate analysis

OBJECTIVES

This study sought to determine whether the reopening of the infarct-related vessel is related to clinical characteristics or cardiovascular risk factors, or both.

BACKGROUND

In acute myocardial infarction, thrombolytic therapy reduces mortality by restoring the patency of the infarct-related vessel. However, despite the use of thrombolytic agents, the infarct-related vessel remains occluded in up to 40% of patients.

METHODS

We studied 295 consecutive patients with an acute myocardial infarction who underwent coronary angiography within 15 days (mean [+/- SD] 6.7 +/- 3.2 days) of the onset of symptoms. Infarct-related artery patency was defined by Thrombolysis in Myocardial Infarction trial flow grade > or = 2. Four cardiovascular risk factors--smoking, hypertension, hypercholesterolemia and diabetes mellitus--and eight different variables-age, gender, in-hospital death, history of previous myocardial infarction, location of current myocardial infarction, use of thrombolytic agents, time interval between onset of symptoms, thrombolytic therapy and coronary angiography--were recorded in all patients.

RESULTS

Thrombolysis in current smokers and anterior infard location on admission were the three independent factors highly correlated with the patency of the infarct-related vessel (odds ratios 3.2, 3.0 and 1.9, respectively). In smokers, thrombolytic therapy was associated with a higher reopening rate of the infard vessel, from 35% to 77% (p < 0.001). Nonsmokers did not benefit from thrombolytic therapy, regardless of infarct location.

CONCLUSIONS

These observational data, if replicated, suggest that in patients with acute myocardial infarction, thrombolytic therapy may be most effective in current smokers, whereas nonsmokers and ex-smokers may require other management strategies, such as emergency percutaneous transluminal coronary angioplasty.

DDD pacing in hypertrophic cardiomyopathy: a multicentre clinical experience

BACKGROUND

DDD pacing has been advocated as an effective treatment for drug refractory obstructive hypertrophic cardiomyopathy. This study reports the outcome of pacing in 56 patients with refractory symptoms referred to four tertiary centres.

METHODS

Core data on symptoms, drug burden, and left ventricular outflow tract gradient were recorded. Patients underwent a temporary pacing study with optimisation of the atrioventricular (AV) delay for greatest gradient reduction without haemodynamic compromise. Patients were assessed after implantation in terms of changes in symptoms, drug load, and outflow tract gradient.

RESULTS

56 patients underwent pacing assessment. The mean (SD) left ventricular outflow tract gradient before pacing was 78 (31) mm Hg. At temporary study the mean (SD) left ventricular outflow tract gradient was 38 (24) mm Hg with a median (range) optimised sensed AV delay of 65 (25-125) ms. Fifty three patients were implanted and followed up for a mean (SD) of 11 (11) months. The median (range) programmed sensed AV delay was 60 (31-200) ms. Left ventricular outflow tract gradient at follow up was 36 (25) mm Hg. Forty four patients had improved functional class. Although a correlation (r = 0.69) was shown between acute and chronic left ventricular outflow tract gradient reduction, there was no correlation between magnitude of gradient reduction and functional improvement, and no appreciable change in pharmacological burden.

CONCLUSION

This series confirms symptomatic improvement after DDD pacing in hypertrophic cardiomyopathy. There remains, however, a discrepancy between perceived symptomatic benefit and modest objective improvement. Furthermore, the optimal outcome has been achieved only with continued pharmacological treatment. Current methods of temporary evaluation do not predict functional outcome which seems to be independent of the magnitude of gradient reduction.

[Results, complications and long-term follow-up of percutaneous ablation of atrioventricular conduction. Apropos of 85 cases]

This retrospective study reports the immediate and long-term results of percutaneous ablation of atrioventricular conduction. Between July 1983 and January 1992, 85 consecutive patients (51 men, age 64 +/- 10 years, range 43-84 years) presenting with supraventricular arrhythmias (atrial fibrillation n = 53; atrial flutter n = 50; atrial tachycardia n = 17; junctional tachycardia n = 6) resistant to antiarrhythmic therapy (number of drugs used: 4 +/- 1.3, range 1-6) underwent interruption of atrioventricular conduction by fulguration (n = 65) or radiofrequency energy (n = 13) or by an association of the two methods (n = 7). The 75 pacemakers implanted (10 patients had pacemakers before the procedure) comprised 55 VVIR, 11 VVI, 5 DDD and 4 DDDR units. The immediate results included two sudden deaths at the 4th and 7th day in patients undergoing fulguration and three complications with a favourable outcome (staphylococcal septicaemia, pulmonary embolism and haematoma at the site of implantation of the pacemaker). None of the patients was lost to follow-up and the average follow-up was 31 +/- 18 months (range 2-108 months). During follow-up, 15 patients died and there was a recurrence of symptoms in 11 patients after 1 to 9 months requiring a repeat procedure. In the 68 survivors, the follow-up is now 38 +/- 18 months (range 12-108 months). Sixty one patients have 2nd (2) or 3rd (59) degree atrioventricular block, giving 90% good electrocardiographic results.(ABSTRACT TRUNCATED AT 250 WORDS)

[Value of permanent cardiac pacing in hypertrophic and obstructive cardiomyopathies resistant to medical treatment]

The authors report their experience of long-term dual-chamber pacing in the treatment of hypertrophic and obstructive cardiomyopathy. Between August 1990 and March 1993, 16 patients (8 men, average age 53.5 +/- 18.9 years, range 21 and 79 years) with symptomatic hypertrophic obstructive cardiomyopathy resistant to medical therapy underwent electrophysiological investigation to assess atrioventricular conduction and the effects of temporary atrioventricular pacing on the intraventricular pressure gradient before implantation of a dual-chamber pacing system. The decision to implant was taken if the endocavitary studies showed severe atrioventricular conduction defects and/or if temporary pacing reduced the systolic pressure gradient by more than 30%. Temporary dual-chamber pacing led to a decrease of 48% of the systolic pressure gradient from 78.6 +/- 21.3 to 40.1 +/- 23.6 mmHg (p < 0.0005), a regression observed in 15 of the 16 patients. After an average follow-up period of 18.7 +/- 9.5 months (range 6 and 37 months), all 15 patients who received a dual-chamber pacing system were alive and were clinically improved. The systolic pressure gradient continued to decrease during the follow-up period (24.4 +/- 17.2 mmHg at the 6th month compared with 36.5 +/- 18.6 mmHg at the time of implantation; p = 0.014). The clinical improvement was dependent on careful adjustment of the atrioventricular delay which was programmed at relatively short values (65.6 +/- 14 ms, range 47 and 75 ms) to obtain permanent right ventricular capture. The authors conclude that dual-chamber pacing is an effective means of treating symptomatic hypertrophic obstructive cardiomyopathy resistant to medical therapy, even in the absence of preexisting conduction defects.

[Influence of gender and size on parameters measured by signal-averaged electrocardiography in healthy subjects: preliminary study]

The aim of this study was to determine the influence of electrocardiographic and biomorphometric factors on the parameters measured by signal averaged electrocardiography (SA-ECG) in normal subjects. The study population comprised 40 Caucasian students (20 men, 20 women). The SA-ECG measured 6 parameters: total duration of the averaged QRS, the root mean square of the voltage of the last 40 ms of the QRS (RMS 40) and the length duration of the terminal signal of under 40 microV (LAS), each parameter being measured with a band pass filter of 25 and 40 Hz. The echocardiographic recording included measurement of 12 parameters including left ventricular mass and ventricular volumes. Five morphological parameters were measured, including height, weight and body surface area. The duration of QRS measured with a 25 Hz band pass filter was significantly longer by 9.7 ms in men than in women (102.9 +/- 8.5 ms versus 93.2 +/- 8.1 ms; p < 0.001). Similarly, QRS duration measured with the 40 Hz band pass filter was longer in men by 11.4 ms than in women (102.1 +/- 9.6 ms versus 90.7 +/- 7.5 ms; p < 0.001). Multiple linear regression analyses showed that in both men and women, the duration of the QRS measured with either a 25 or 40 Hz band pass filter was correlated to size: the taller the subject, the longer the QRS duration. A negative correlation was observed between size and RMS 40 measured with both 25 and 40 Hz band pass filters: the taller the subject, the smaller the value of RMS 40.(ABSTRACT TRUNCATED AT 250 WORDS)

Phosphorus magnetic resonance spectroscopy: a noninvasive technique for the study of occlusive arterial leg disease and peripheral vasodilator therapy

Using 31P nuclear magnetic resonance spectroscopy of the calf muscle, the authors studied patients with peripheral arterial occlusive disease. They studied PCr depletion and intracellular pH during aerobic exercise in patients and controls. The phosphocreatine (PCr) index ([PCr]/([PCr] + [Pi])) at rest was correlated with blood flow measured by plethysmography. During aerobic exercise a greater decrease in pH was obtained in patients (p < 0.03). They also studied the work necessary to reach a PCr index = 0.5 during ischemic exercise. This workload was lower in patients than in controls: 32.99 +/- 3.04 J vs 58.89 +/- 8.55 J, p < 0.05. After vasodilator therapy the workload was improved in patients: 32.99 +/- 3.04 J vs 38.85 +/- 3.54 J, p < 0.05. These results suggest that therapy resulted in improved tissue perfusion in patients.

Contained morselized allograft in revision total hip arthroplasty. Surgical technique

The current technique and instrumentation for contained morselized allograft with cement in dealing with femoral loosening associated with loss of bone stock is described. With a follow-up extending to 6 years, this method has proved effective in the management of these difficult problems.

[Atrioventricular block induced by radiofrequency: electrophysiological criteria of success]

In a retrospective series of 18 consecutive patients (10 men, average age: 61.6 +/- 9.2 years) who underwent His bundle ablation by radiofrequency current, the authors analyzed the electrophysiological criteria predictive of complete atrioventricular block. A total of 82 radiofrequency bursts were analyzed (average: 4.5 +/- 3.1 bursts/patient) and classified as effective (N = 14, definitive atrioventricular block), ineffective (N = 55, no effect on atrioventricular conduction) or transiently effective procedures (N = 13, reversible Mobitz II atrio-ventricular block). Seven electrophysiological parameters were measured: HV interval, amplitude of atrial (A), Hisian (H) and ventricular (V) potentials, and the A/H, A/V, and V/H ratios before each radiofrequency burst. At the end of the ablation, 14 patients were in complete atrioventricular block and during the following 24 hours, a complete atrioventricular block developed in 3 other patients. The average value of the H potential was comparable in the effective and transiently effective procedures (0.28 +/- 0.20 mV and 0.27 +/- 0.19 mV respectively) and significantly higher than the same parameters in the ineffective group of procedures (0.65 +/- 0.14 mV, p = 0.008). The V/H ratio was progressively greater in effective (5.43 +/- 2.51), transiently effective (8.07 +/- 6.90) and ineffective procedure (14.32 +/- 13.35), p = 0.02; the average value of the A amplitude tended to be higher in the effective procedures (1.03 +/- 0.75 mV) and the transiently effective procedures (0.98 +/- 0.72 mV) than in the ineffective procedures (0.58 +/- 0.79 mV), p = 0.06. On the other hand, the other parameters were comparable in the three groups of patients.(ABSTRACT TRUNCATED AT 250 WORDS)

[Severe hyponatremia disclosing adenohypophyseal insufficiency with empty sella syndrome]

We report a case of extremely severe hyponatraemia which led to the discovery of anterior hypophysis insufficiency associated with empty sella turcica in a dysimmune context. This type of hyponatraemia is consecutive to corticotropic and thyreo-tropic hormones deficiency and to inappropriate secretion of arginine vasopressin. These endocrine abnormalities are of suprapituitary origin. They can be explained by a hypothalamo-hypophyseal dysregulation of little known mechanism, or by a lesion of the hypothalamus.

Impacted cancellous allografts and cement for revision total hip arthroplasty

We report the results of using impacted cancellous allografts and cement for fixation of the femoral component when revision arthroplasty is required in the face of lost bone stock. In 56 hips reviewed after 18 to 49 months there were few complications and a majority of satisfactory results with evidence of incorporation of the graft. Further study and review are necessary, but the use of the method appears to be justified.

Modulation of the immunosuppressive activity of CKS-17, a synthetic retroviral envelope peptide, by muramyl dipeptide

CKS-17, a heptadecapeptide corresponding to a region highly conserved in retroviral transmembrane proteins is known to be immunosuppressive both in vitro and in vivo when conjugated to a carrier protein. Here we examined the effect of the synthetic adjuvant muramyl dipeptide (MDP) on the immunosuppressive properties of CKS-17-BSA in vitro. MDP was found to abrogate CKS-17-BSA-induced inhibition of both IgM plaque-forming cell responses and antitetanus toxin IgG secretion by BALB/c mouse spleen cells immunized in vivo and in vitro by sheep red blood cells and tetanus toxoid, respectively. In contrast, the CKS-17-BSA suppression of concanavalin A-induced splenocyte proliferation was not abrogated by MDP. The data suggest that muramyl peptides could be useful as immunoadjuvants for vaccines against retrovirus-associated immunosuppressive diseases.

Implication of the HLA-DRB3 gene in Graves' disease: predominance of allele Dw24

Using RFLP, the present study sets off to determine the MHC class II gene polymorphism in Graves' disease, in order to define the HLA-related genetic susceptibility. Considering the preferential link between Graves' disease and the HLA-DR3 antigen, 42 HLA-DR3 Graves' disease patients were studied and compared with 42 HLA-DR-matched controls. Hybridization with a DQ alpha probe of DNAs digested by Taq I revealed a polymorphism of the DR3 haplotype with an overrepresentation of a 2.1 kb(U) fragment in patients, but this was merely a sign of the linkage disequilibrium between U and B8DR3. Hybridization with the DR beta probe of DNAs digested by Taq I yielded more facts. It revealed the overrepresentation of the Dw24 specificity (Taq I:9.8 kb) in DR3 Graves' disease patients. This study thus enabled us to determine precisely the susceptibility linked to the DR3 haplotype, implicating the DRB3 gene and its Dw24 allele, which appear to be the most reliable markers of the disease, providing a higher relative risk than B8DR3.