Biomedical subjects
A Marzouki
Publications and source records attributed to A Marzouki.
[Fenton's syndrome or scapho-capitate fracture (a case report)].
INTRODUCTION: Scapho-capitate fracture is a rare lesion and its mechanism is controversial. Forced extension seems to be the most frequent cause as this movement of the wrist induces scaphoid fracture by compression. Hyperextension of the wrist as a result of the scaphoid lesion, allows contact between the posterior margin of the radius and the neck of the capitate inducing a capitate fracture. MATERIALS AND METHODS: We report a case of Fenton's Syndrome, the patient was operated as an emergency by pining and immobilization of the carpus and thumb until bone consolidation had occurred. RESULTS: Consolidation was noted at 8 weeks with a good mobility of the wrist. DISCUSSION: Fenton's Syndrome is a rare lesion of the wrist. Analysis of our own case and a review of literature demonstrated extension as a causative mechanism, and the frequency of delayed diagnosis. Because of the presence of instability, scaphoid reduction and osteosynthesis is necessary. Immobilization of the carpus and thumb is essential until bony consolidation is obtained.
[Coverage of tissue loss in the upper limb (ten cases)].
PURPOSE OF THE STUDY: The purpose of this study was to evaluate early cover of post-traumatic tissue loss in the upper limb. MATERIAL AND METHODS: We report 10 cases of tissue loss in the upper limb treated surgically by fasciocutaneous flaps or muscle flaps. The patients were aged from 14 to 60 years. Six patients underwent surgery as an emergency. Surgery consisted of a thorough debridement, internal fixation if required and soft tissue reconstruction as indicated. This was then followed by immediate flap cover. All had antibiotics during and after surgery. The coverage procedure was selected according to the site and its dimensions. We used 8 fasciocutaneous and 2 muscle flaps in our series. RESULTS: One flap underwent necrosis. The flaps otherwise showed good scaring and trophicity. All the patients were satisfied. DISCUSSION: Early or even immediate coverage of substantial tissue loss following trauma has been made possible because of the development of newer flap techniques. Meyer considers that the improved results can be explained by the fact that early cover prevents bone and tendon desiccation and is achieved before substantial bacterial colonisation can occur. Additionally it is a reliable procedure that brings in vascularised tissue, thereby contributing to reduced scarring of the underlying structures. It also permits immediate osteosynthesis thus avoiding the problems of external fixation. To us the key advantage of emergency skin cover is the fact that the operative field may become colonised but does not become infected. This gives the surgeon the freedom to undertake immediate reconstruction without the prospect of subsequent sepsis.
Transplantation of the human uterus.
Human uterine transplantation was performed on 6 April 2000 on a 26-year-old female who lost her uterus 6 years earlier due to post-partum hemorrhage. The donor, a 46-year-old patient with multiloculated ovarian cysts, underwent a hysterectomy modified to preserve tissue and vascular integrity. The donor uterus was connected in the orthotopic position to the recipient's vaginal vault and additional fixation was achieved by shortening the uterosacral ligament. The uterine arteries and veins were extended using reversed segments of the great saphenous vein, then connected to the external iliac arteries and veins, respectively. Immunosuppression was maintained by oral cyclosporine A (4 mg/kg/body wt.), azathioprine (1 mg/kg/body wt.) and prednisolone (0.2 mg/kg/body wt.). Allograft rejection was monitored by Echo-Doppler studies, magnetic resonance imaging (MRI), and measurement of the CD4/CD8 ratio in peripheral blood by fluorescence activated cell sorter (FACS scan). An episode of acute rejection was treated and controlled on the ninth day with anti-thymocytic globulin (ATG). The transplanted uterus responded well to combined estrogen--progesterone therapy, with endometrial proliferation up to 18 mm. The patient had two episodes of withdrawal bleeding upon cessation of the hormonal therapy. Unfortunately, she developed acute vascular thrombosis 99 days after transplantation, and hysterectomy was necessary. Macro- and microscopic histopathological examination revealed acute thrombosis in the vessels of the uterine body, with resulting infarction. Both fallopian tubes remained viable, however, with no evidence of rejection. The acute vascular occlusion appeared to be caused by inadequate uterine structure support, which led to probable tension, torsion, or kinking of the connected vascular uterine grafts.
Reproducibility and validity of laser flare/cell meter measurements of intraocular inflammation.
Preoperative and postoperative anterior chamber reactions in a series of cataract surgery patients were measured with a Kowa FC-1000 laser flare/cell meter by two different technicians, and clinical assessments of inflammation were recorded. The average cell and flare readings by the two technicians were nearly identical at every time point, showing the laser flare/cell measurements to be highly reproducible. The correlations between laser flare/cell measurements and clinical assessments at postoperative time points were highly positive (P < .01), demonstrating the validity of the laser flare/cell measurements.
Reproducibility and validity of laser flare/cell meter measurements as an objective method of assessing intraocular inflammation.
Preoperative and postoperative anterior chamber reactions in a series of patients who had undergone cataract surgery were measured with a laser flare/cell meter (Kowa FC-1000, Kowa Instrument Corp, Japan) by two different technicians (A.M. and T.M.M.), and clinical assessments of inflammation were recorded. The average cell and flare readings of the two technicians were nearly identical at every time point, showing the laser flare/cell measurements to be highly reproducible. The correlations between laser flare/cell measurements and clinical assessments at postoperative time points were all highly positive (P less than .01), demonstrating the validity of the laser flare/cell measurements.
Leukemic infiltrate versus anterior uveitis.
Anterior segment leukemic infiltrate (ASLI) is rare; it is found in 0.5% to 2.5% of all leukemic relapses. Its clinical manifestations, at times, are similar to those of anterior uveitis (AU). We report the cases of three patients, all of whom had ASLI as their primary manifestation of relapse. We observed some major clinical differences between ASLI and AU that may help differentiate these two conditions without using anterior chamber paracentesis and/or iris biopsy. The development of resistance to leukemic therapy is the major factor in treatment failure.
Modification of the reactivity of three amino-acid residues in elongation factor 2 during its binding to ribosomes and translocation.
The accessibility of three amino acids of EF-2, located within highly conserved regions near the N- and C-terminal extremities of the molecule (the E region and the ADPR region, respectively) to modifying enzymes has been compared within nucleotide-complexed EF-2 and ribosomal complexes that mimic the pre- and posttranslocational ones: the high-affinity complex (EF-2)-nonhydrolysable GTP analog GuoPP[CH2]P ribosome and the low-affinity (EF-2)-GDP-ribosome complex, EF-2 and ribosomes being from rat liver. We studied the reactivity of two highly conserved residues diphthamide-715 and Arg-66, to diphtheria-toxin-dependent ADP-ribosylation and trypsin attack, and of a threonine that probably lies between residues 51 and 60, to phosphorylation by a Ca2+/calmodulin-dependent protein kinase. Diphthamide 715 and this threonine residue were unreactive within the high-affinity complex but seemed fully reactive in the low-affinity complex. Arg-66 was resistant to trypsin in both complexes. The possible involvement of the E and ADPR regions of EF-2 in the interaction with ribosome in the two complexes is discussed.
Modification of the accessibility of ribosomal proteins after elongation factor 2 binding to rat liver ribosomes and during translocation.
Free- and EF-2-bound 80 S ribosomes, within the high-affinity complex with the non-hydrolysable GTP analog: guanylylmethylenediphosphonate (GuoPP(CH2)P), and the low-affinity complex with GDP, were treated with trypsin under conditions that modified neither their protein synthesis ability nor their sedimentation constant nor the bound EF-2 itself. Proteins extracted from trypsin-digested ribosomes were unambiguously identified using three different two-dimensional gel electrophoresis systems and 5 S RNA release was checked by submitting directly free- and EF-2-bound 80 S ribosomes, incubated with trypsin, to two-dimensional gel electrophoresis. Our results indicate that the binding of (EF-2)-GuoPP[CH2]P to 80 S ribosomes modified the behavior of a cluster of five proteins which were trypsin-resistant within free 80 S ribosomes and trypsin-sensitive within the high-affinity complex (proteins: L3, L10, L13a, L26, L27a). As for the binding of (EF-2)-GDP to 80 S ribosomes, it induced an intermediate conformational change of ribosomes, unshielding only protein L13a and L27a. Quantitative release of free intact 5 S RNA which occurred in the first case but not in the second one, should be related to the trypsinolysis of protein(s) L3 and/or L10 and/or L26. Results were discussed in relation to structural and functional data available on the ribosomal proteins we found to be modified by EF-2 binding.
Heterogeneity of native rat liver elongation factor 2.
The high heterogeneity of native rat liver EF-2 prepared from either 105000 x g supernatant or microsome high-salt extract was detected by two-dimensional equilibrium isoelectric focusing-SDS-polyacrylamide gel electrophoresis in the presence of 9.5 M urea. Five spots were always detected, all of Mr 95,000, which were not artefactual for their amount varied when EF-2 was specifically ADP-ribosylated by diphtheria toxin in the presence of NAD+, and/or phosphorylated on a threonine residue by a Ca2+/calmodulin-dependent protein kinase (most likely Ca2+/calmodulin-dependent protein kinase III described by others [(1987) J. Biol. Chem. 262, 17299-17303; (1988) Nature 334, 170-173]). Results of ADP-ribosylation and/or phosphorylation experiments with either unlabeled or labeled reagents ([14C]NAD and [32P]ATP) strongly suggest that our preparation contained native ADP-ribosylated and native phosphorylated forms which could be estimated at about 20% and 40% of the whole EF-2. Phosphorylated and ADP-ribosylated forms of EF-2 could be ADP-ribosylated and phosphorylated, respectively, but a native form both ADP-ribosylated and phosphorylated was not detected. Our results also suggest the existence of a minor native form of EF-2 and of its phosphorylated and ADP-ribosylated derivatives.
Heterogeneity of ribosomal autoantibodies from human, murine and canine connective tissue diseases.
Antiribosomal auto-antibodies (anti-Rib.Ab) have been studied in connective tissue diseases (human, dog and mouse) by immunoblotting after one-dimensional (1D) or two-dimensional (2D) gel electrophoresis of rat ribosomes. Anti-Rib.Ab could be found in systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and other connective tissue diseases (progressive systemic sclerosis, PSS; Sjögren syndrome, SjS; mixed connective tissue disease, MCTD; and dermatomyositis, DM with the frequencies 41.7%, 54.6% and 33%, respectively. Immunoblotting after 1D gel electrophoresis showed the great heterogeneity of ribosomal proteins recognized by the anti-Rib.Ab. In the SLE, however, the most frequent antibodies stained bands of the 40S subunit: 30 kDa (34% of positive sera), 19.5 kDa (24.5%) and 43 kDa (17%). In RA, the 25-kDa band of the 60S subunit was the most common (54% of positive sera). In the other human connective tissue diseases, there was no particular predominance. In the MRL/1, anti-Rib.Ab were very frequent (92.6%). The 43-kDa band of the 40S subunit was found in 100% of positive sera. Seventeen out of nineteen dogs with SLE gave positive results on immunoblot, and all of them stained the 43-kDa band of the 40S subunit. 2D gel electrophoresis gave identification of Po, L7, L5, Sb, S19, S13 and L2 proteins in SLE, S3 and SjS, L35a and L37a in RA, and L7, S6 and/or L7a in MRL/1.
Reconstitution of the active rat liver 60 S ribosomal subunit from different preparations of core particles and split proteins.
Proteins extracted from the 60 S rat liver ribosomal subunit with 50% ethanol/0.5 M K Cl produced only a partial reactivation of the corresponding core particles. In contrast, the same split proteins were able to reactivate the core particles prepared with dimethyl-maleic anhydride (DMMA) to the same level as that observed using the DMMA-split proteins, i.e. 60-80% of the control according to the catalytic activities tested. Comparative analysis of the two split protein fractions showed only four common proteins: P1-P2, which alone restored part of the activities, especially the EF-2-dependent GTPase one, and L10a, L12, which must be responsible for the additional reactivation. The poor ability of the ethanol/KCl core particles to be reactivated was shown to be probably related to a conformational alteration which destabilized the 5 S RNA-protein complex. Proteins present in the ethanol/KCl wash of Saccharomyces cerevisiae 60 S subunits were found to be partly active in subunit reconstitution using rat liver DMMA core particles.
Topography and stoichiometry of acidic phosphoproteins in rat liver 60 S ribosomal subunit.
In reconstitution experiments of active 60 S subunits from inactive core particles obtained by using dimethyl maleic anhydride (DMMA), we observed that the phosphoproteins P1-P2 were extracted from the subunit by DMMA as a complex with other proteins. This complex was separated by electrophoresis and zonal centrifugation and shown, after 125I iodination of its components, to contain L22 and S12 in addition to P1-P2. Results suggest that it contains two copies of P1-P2 for one of L22 and S12.
Effect of ADP-ribosylation and phosphorylation on the interaction of elongation factor 2 with guanylic nucleotides.
Samples of unmodified EF-2, EF-2 ADP-ribosylated with diphtheria toxin and NAD, and/or phosphorylated using ATP and the Ca(2+)-calmodulin dependent kinase III partially purified, were irradiated at 254 nm with 32P-labeled GDP or GTP, and analyzed by one- and two-dimensional gel electrophoresis. By this method we showed that unmodified EF-2 formed a stable complex with GDP but not with GTP, whereas phosphorylated EF-2 and ADP-ribosylated + phosphorylated EF-2 formed stable complexes even in the absence of irradiation, with GTP but not GDP. ADP-ribosylated EF-2 did not form stable complexes with either GDP or GTP. Prior ADP-ribosylation of EF-2 increased its ability to the phosphorylated. These results show that the structures of the two domains containing diphtamide 715 and the phosphorylatable threonines (between Ala 51 and Arg 60) are interdependent; modifications of these residues induce different conformational changes of EF-2 which alter the interactions of the factor with guanylic nucleotides as well with ribosomes.