Assessment of organ dose and image quality in head and chest CT examinations: a phantom study.

The purpose of this study is to assess dose for radiosensitive organs and image quality in head and chest computed tomography (CT) examinations. Our focus was in the brain, eye lens and lung organs using two protocols; one protocol with fixed mAs and filtered back projection (FBP) and another with tube current modulation (TCM) and sinogram affirmed iterative reconstruction (SAFIRE). Measurements were performed on a 128-slice CT scanner by placing thermoluminescent dosimeters (TLDs) in an anthropomorphic adult phantom. Results were compared to a CT-Expo software. Objective image quality was assessed in terms of signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). SPSS software was used for data analyses. Results showed that, using TCM, doses were reduced by 22.84%-25.06% for brain, by 21.82%-23.48% for eye lens and by 54%-53.22% for lung with TLD and CT-Expo respectively. The increased SNR and CNR values achieved for scans performed with TCM combined with iterative reconstruction techniques were 38.68%-58.81% and 38.91%-43.60% respectively. We conclude that, using TCM, a significant mean organ dose reduction is achieved for brain, eye lens and lung organs. Then, combined with iterative reconstruction, image quality was well maintained in terms of SNR and CNR. Thus it is highly recommended in clinical practice optimization in head and chest CT examinations.

Total knee arthroplasty with the Medial-Pivot knee system: Clinical and radiological outcomes at 9.5 years' mean follow-up.

INTRODUCTION: The "ball-in-socket" design of the Medial-Pivot knee system (MicroPort Orthopedics, Arlington, Tennessee, USA) aims to reproduce normal knee kinematics by medializing its rotational axis. The goal of this study was to measure knee range of motion (ROM) with this implant after a mean follow-up of 10 years and to report the survivorship and long-term clinical and radiological outcomes. We hypothesized the prosthetic knee would have at least 120° flexion at 10 years. MATERIAL AND METHODS: This was retrospective, single-centre study of 74 Medial-Pivot knees implanted in 71 patients (average age of 69 years) between May 2005 and November 2007. All patients who received a Medial-Pivot knee were included consecutively. The mean follow-up was 10 years. Clinical and radiological assessments were performed using the Knee Society Score (KSS) and Ewald's score. Kaplan-Meir survival analysis was used to calculate survivorship. RESULTS: Seven percent of cases were lost to follow-up. The knee ROM was 110° at 10 years. The survivorship was 93% for all revision causes and 95.9% when revisions due to trauma or infection were excluded. The mean KSS score was 195. Stable radiolucent lines were found in 14% of cases. No aseptic loosening was observed. CONCLUSION: Our hypothesis was not confirmed. Knee flexion at the final follow-up was comparable to other semi-constrained implant designs but was not as large as expected. The survival of the Medial-Pivot knee at 10 years is good. Its radiological and clinical outcomes are satisfactory. LEVEL OF EVIDENCE: IV (retrospective cohort study).

Total hip arthroplasty revision by dual-mobility acetabular cup cemented in a metal reinforcement: A 62 case series at a minimum 5 years' follow-up.

INTRODUCTION: Total hip arthroplasty (THA) requires bone reconstruction in case of severe acetabular injury, with risk of dislocation, especially postoperatively. Dual-mobility cups have proved effective in preventing dislocation in THA revision for instability, but their behavior when cemented in a metal reinforcement has been little studied. OBJECTIVES: The present study assessed results for a dual-mobility cup cemented in a metal reinforcement, in terms of aseptic loosening and postoperative instability. MATERIAL AND METHODS: A single-center continuous series of 62 patients receiving such an assembly in THA revision was assessed retrospectively at a minimum 5 years' follow-up. Failure due to aseptic loosening or instability and implant survival at last follow-up were analyzed. RESULTS: Radiological and clinical analysis was performed at a mean 77 months' follow-up. Mean Merle-d'Aubigné-Postel score was 14, Harris score 73 and Oxford-12 score 23.9 at last follow-up. Complications comprised 5 cases of loosening and 2 of dislocation. Loosening risk was significantly greater in case of<2mm cement thickness between cup and reinforcement. Eight-year infection-free survival was 91.9%. DISCUSSION: The present clinical results were comparable to those in series using the same kind of assembly; the dislocation rate was low, but the rate of aseptic loosening was higher than reported elsewhere. Cement thickness between cup and reinforcement was a determining factor for stability. Cup design may also be relevant to loosening. This technique seemed to be a good option in THA revision with severe bone loss. LEVEL OF EVIDENCE: IV, retrospective study.

Results of 115 Rubis II reverse thumb carpometacarpal joint prostheses with a mean follow-up of 10 years.

The aim of this study was to assess the clinical and radiological results of the Rubis II thumb carpometacarpal joint reverse prosthesis, at a mean follow-up of 10 years. Between 1997 and 2008, 253 prostheses were implanted in 199 patients; 115 were reviewed. The survival after a mean of 10 years was 89%. At the last follow-up, 70% of prostheses were painless; the others reported moderate or intermittent pain. The satisfaction rate was 98%. The mean opposition was 9 on the Kapandji scale; the mean QuickDASH score was 30. Wrist, key and tip pinch strengths were comparable with the non-operated side. Of the 115 implants, one was radiologically loose (1%) and 15 had suffered dislocations (13%), 12 of which were caused by an injury. Eleven thumbs had revision surgery. This study confirms that the good clinical results of the Rubis II prosthesis are maintained in the medium and long term, and represents a useful alternative to trapeziectomy for selected patients. LEVEL OF EVIDENCE: IV.

[Myocardial infarction after conduction electrical weapon shock]. / Infarctus du myocarde suite à une électrisation par pistolet à impulsion électrique.

Controversy persists over the safety of conducted electrical weapons, which are increasingly used by law enforcement agencies around the world. We report a case of 33-year-old man who had an acute inferior myocardial infarction after he was shot in the chest with an electrical weapon.

Assessment of acrosome and nuclear abnormalities in human spermatozoa with large vacuoles.

BACKGROUND: Spermatozoa with large vacuoles (SLV) may have a negative impact on embryo development. The origin of these vacuoles is unknown. We evaluated acrosome and nucleus alterations in isolated SLV, versus unselected spermatozoa. METHODS: We studied 20 patients with teratozoospermia. Spermatozoa from the native semen sample and spermatozoa presenting a vacuole occupying >13.0% total head area, isolated under high magnification (×6600), were assessed. Confocal and transmission electron microscope evaluations were performed on SLV and native sperm, respectively. Acrosome morphology and DNA fragmentation were analysed using proacrosin immunolabelling (monoclonal antibody 4D4) and terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling assay. Chromatin condensation was evaluated with aniline blue staining. Sperm aneuploidy was assessed using fluorescence in situ hybridization. RESULTS: SLV represented 38.0 ± 5.10% of motile spermatozoa obtained after gradient density centrifugation. Vacuoles were mainly in the anterior and median sperm head (45.7 ± 2.90 and 46.1 ± 3.00%, respectively). Abnormal acrosomes were increased in SLV compared with unselected spermatozoa (77.8 ± 2.49 versus 70.6 ± 2.62%; P = 0.014). Microscopic observations showed an exclusively nuclear localization of large vacuoles. Complete DNA fragmentation was higher in native spermatozoa (P < 0.0001) than SLV, while chromatin condensation was altered in SLV (P < 0.0001). Aneuploidy and diploidy rates were increased in SLV (P < 0.0001). CONCLUSIONS: Sperm vacuoles were exclusively nuclear. In our selected teratozoospermic population, aneuploidy and chromatin condensation defects were the main alterations observed in SLV. Based on results from this small sample of spermatozoa, we propose a global impairment of the spermatogenesis process as a common origin of the morphological alterations.

Prevalence of inherited prothrombotic abnormalities and central venous catheter-related thrombosis in haematopoietic stem cell transplants recipients.

In this prospective study, we assessed the incidence of central venous catheter (CVC)-related thrombosis in haematopoietic stem cell transplant (HSCT) recipients. We determined the contribution of inherited prothrombotic abnormalities in blood coagulation to CVC-related thrombosis in these patients. The study was conducted between May 2002 and September 2004. CVCs were externalized, nontunneled, polyurethane double lumen catheters. Before catheter insertion, laboratory prothrombotic markers included factor V Leiden, the prothrombin gene Gly20210A mutation, plasma antithrombin levels, and protein C and S activity. All patients were systematically examined by ultrasonography just before, or <24 h after, catheter removal, and in case of clinical signs of thrombosis. A total of 171 patients were included during the 28-month study period. Five (2.9%) and three (1.7%) patients had evidence of protein C and protein S deficiency, respectively. Only one patient had an antithrombin deficiency (0.6%). In total, 10 patients (5.8%) were heterozygous for the factor V Leiden mutation, and one patient had heterozygous prothrombin G20210A mutation (0.6%). We observed a CVC-related thrombosis in 13 patients (7.6%). Thrombosis was diagnosed in four out of 20 patients (20%) with a inherited prothrombotic abnormality compared to nine of 151 patients (6%) who did not have a thrombophilic marker (relative risk 3.3 CI 95% 1.1-9.9). Our results suggest that inherited prothrombotic abnormalities contribute substantially to CVC-related thrombosis in HSCT recipients. In view of physicians' reluctance to prescribe prophylactic anticoagulant treatment in these patients, a priori determination of inherited prothrombotic abnormalities may form a basis to guide these treatment decisions.

Palmitoyl derivatives of GpMBP epitopes: T-cell response and peptidases susceptibility.

We report for the first time the immunoadjuvant effects of lipoconjugation of peptide antigens in an in vitro system by using CD4+ T-cells. The lipopeptides obtained by conjugating a palmitoyl moiety at the N(alpha)-terminal of Gln(74) or at the epsilon-NH(2) of Lys(75) of GpMBP(74-85) induced increased T-cell responsiveness compared to the native nonlipidated peptide. On the other hand, lipoderivatives of GpMBP(82-98) did not increase the T-cell response, demonstrating that the superagonist inducing effect of lipoconjugation is epitope-specific. Digestion of the two native peptides with cathepsin D and L, both implicated in antigen processing, and with a complete lysosomal fraction of a EBV-transformed B cell line shows that GpMBP(74-85) is resistant to cellular proteases, while GpMBP(82-98) is easily digested by these enzymes. These results suggest that the first prerequisite for increasing the T-cell response by lipoconjugation is the stability of the native peptide to peptidases, providing an important insight into the understanding of the immunoadjuvant effect of lipoderivative antigens.

Determinants of the trans-dominant negative effect of truncated forms of the CCR5 chemokine receptor.

The human immunodeficiency virus, type 1 (HIV-1) entry process is triggered by interaction between the viral envelope and a seven membrane-spanning domain receptor at the cell surface, usually the CCR5 chemokine receptor. Different naturally occurring mutations in the CCR5 gene abolish receptor function, the most frequent being a 32-nucleotide deletion resulting in a truncated protein (Delta32) lacking the last three transmembrane domains (TM5-7). This mutant is retained in the endoplasmic reticulum and exerts a trans-dominant negative (TDN) effect on the wild type, preventing its exit from this compartment. This TDN effect is often considered as evidence for the oligomerization of CCR5 during transport to the cell surface. Here we use a genetic approach to define the structural determinants of the TDN effect of the Delta32 mutant. It was abolished by certain deletions and by mutations of cysteine residues preventing formation of a disulfide link between the first and second extracellular loops, suggesting that conformation of Delta32 is important for its interaction with CCR5. To circumvent this problem, we used chimeric forms of the Delta32 and wild type CCR5, consisting in substitutions with homologous domains from the mouse CCR5. All chimeric full-length receptors were expressed at the cell surface and were functional for interaction with HIV-1 or with a chemokine ligand, when assayed. The TDN effect was only observed if both the TM3 domain in CCR5 and the TM4 domain in Delta32 were from human origin, whereas the rest of the proteins could be from either origin. This suggests that the TDN effect involves some form of interaction between these transmembrane domains. Alternatively, but less likely to us, substitutions in TM4 could affect the conformation of CCR5 in the endoplasmic reticulum but not at the cell surface. However that may be, it seems that the TDN effect of the Delta32 mutant has no bearing to the issue of CCR5 dimerization and to its possible role in the processing of the receptor to the cell surface.

[Pelvic ganglioneuroma. Case report]. / Ganglioneurome pelvien. A propos d'un cas.

Ganglioneuroma is a neurogenic tumor originating from autonomic ganglia. It most commonly occurs in patients younger than 20 years with a slight predominance of females. The pelvic localization is rare. Imaging can lead to diagnosis but it is not specific. The diagnosis can only be confirmed by the pathologic study. The authors report one case of pelvic ganglioneuroma diagnosed in an 11-year-old child who also had hypertension and renal failure.

[Diabetic fibrous mastopathy]. / La mastopathie fibreuse diabétique.

Diabetic fibrous mastopathy was first described in 1984. This mastopathy usually occurs in patients with autoimmune disorders and often occurs in patients with insulin-dependent diabetes. Little is known about this benign condition. Clinically and radiologically, this entity may simulate malignancy. The presence of an underlying auto-immune disorder or diabetes may suggest the correct diagnosis. The authors report two cases of fibrous mastopathy and suggest that core biopsy could replace surgical biopsy for diagnosis.

A synthetic glycopeptide of human myelin oligodendrocyte glycoprotein to detect antibody responses in multiple sclerosis and other neurological diseases.

Glycopeptides of hMOG(30-50) containing a glucosyl moiety on the side-chains of Asn, Ser or Hyp at position 31 were synthesised. Antibody titres to hMOG(30-50) and to its glucoderivatives were measured by ELISA in sera of patients affected by different neurological diseases. Anti-hMOG(30-50) antibodies were detected only using the glycopeptide [Asn31(N-Glc)]hMOG(30-50).

An in vivo, ex vivo and in vitro comparative study of activity of copper oligopeptide complexes vs Cu(II) ions.

The tetrapeptide-Cu(II) complex H-(l-His-Gly)2-OH/Cu(II), indicated as L-Cu(II), has been investigated, as compared to the Cu(II) inorganic salt CuSO4, for its antioxidative and anti-inflammatory properties under a panel of experimental conditions. Both inorganic and organic Cu(II) compounds showed comparable activities in vitro and ex vivo by: (i) protecting, in a dose-dependent manner, rat brain homogenates from Fe(III)/ascorbate- or haemoglobin-induced lipid peroxidation; (ii) inhibiting the superoxide-mediated ferricytochrome c reduction by activated macrophages. CuSO4 and L-Cu(II) also exhibited similar anti-inflammatory effects in vivo by reducing significantly the extent of carrageenan-induced edema in the rat paw. The activities of the two compounds diverged strikingly only in the xanthine/xanthine oxidase system at low phosphate buffer concentration. L-Cu(II) decreased the rate of NBT reduction by superoxide in a true SOD-like fashion without affecting urate production. Instead, Cu(II) ions caused the rapid xanthine oxidase inactivation thus inhibiting both urate and superoxide production; this effect might be ascribed to the superoxide-mediated generation of the strong oxidant Cu(III) and its interaction with the enzyme. The administration of Cu(II), whether complexed with linear oligopeptides or as an inorganic salt, to animals or tissue extracts, conferred protection against oxidation and ought, conceivably, to interact with endogenous biological molecules and form highly bioavailable complexes which serve, subsequently, as the real scavengers. Moreover, the claimed prominent scavenger activities of Cu(II)-oligopeptide complexes over inorganic copper ions could be realised only in very simple in vitro systems through mechanisms which, although of biochemical interest, are unlikely to be of physiopathological significance.

Histidyl-glycyl containing peptides. Characterization complexation properties of H(L-His-Gly)2-R with hydrogen and alkali metal ions in the gas phase.

The two histidyl-glycyl containing peptides, H(L-His-Gly)2-OH and its methyl ester (H(L-His-Gly)2-OCH3, have been structurally characterized by liquid secondary-ion mass spectrometry. Both high-internal-energy ion fragmentations produced in the source and metastable decompositions occurring in the first field-free region have been studied. The mass spectra show the presence of y-, a- and b-type ions, a1 being the most abundant fragment ion. The metastable decompositions are dominated by the loss of a water molecule and by y-type ions. The interactions of the two peptides with alkali metal ions (Li, Na, K) have been evaluated both by normal mass spectrometry and by tandem mass spectrometry to obtain selected daughter-ion spectra. The occurrence of mono-, bi- and trimetallated species has been detected in the gas phase. While, in the case of the protonated species, y-type ions are predominant, in the presence of an alkali metal ion (Cat), they show lower abundances (Cat = Li) or are absent (Cat = Na, K) both in the mass spectra produced in the source and in metastable decompositions. In most of these cases, a very intense low-internal-energy ion, which is represented by [a3 + Cat - H]+ and which can be produced by interaction of the metal with a deprotonated amide nitrogen, is recorded. This mechanism should be favored by the ¿anchoring¿ effect exerted by the imidazole ring of the histidine which promotes interaction with metals. Other metastable decompositions yield abundant [b3 + Cat - H]+ ions or involve the loss of the side-chain of the histidine. The formation of [b3 + Cat +OH]+ ions, observed only in the case of the free acid peptide, is due to the interaction of the metal ion with the C-terminus carboxyl group. Bi- and trimetallated species have also been detected in the gas phase and characterized.

[Anatomo-clinical characteristics of ovarian fibrothecal tumors. 19 cases over 12 years: 1981-1992[]. / Caractéristiques anatomo-cliniques des tumeurs fibrothécales de l'ovaire. A propos de dix-neuf cas en douze ans: 1981-1992.

The quasi-constantly benign nature of fibrithecomas of the ovary has been known for many years. However, there have been very few studies of their incidence and clinical characteristics. The aim of this study, based upon 19 cases of fibrothecal tumours of the ovary operated upon at the Rabta maternity unit during a 12 year period, is to give an idea as to epidemiological factors, diagnostic conditions and treatment methods used among the women studied.

[Abdominal pregnancy, a rare anatomoclinical entity. 4 case reports (1981-1990)]. / La grossesse abdominale, entité anatomoclinique rare. A propos de 4 cas (1981-1990).

The opportunity is taken, on the basis of 4 cases of abdominal pregnancy and a review of the literature, to attempt to analyse the various aspects of this increasingly rare pathology. Its incidence is low, being evaluated by our own study at 4/85 757 deliveries, i.e.: 1/21 439 deliveries collected at the Maternity and Neonatology centre of Rabta Tunis during a 10-year period (1981-1990). The essential epidemiological factor is the low socio-economic and cultural status seen in the patients studied. Clinical signs were predominated by metrorrhagia, abdominal pain, disturbed intestinal function and fetal death in utero. The delay in diagnosis explains the onset of frequent fetal complications in the form of fetal death in utero (3 cases out of 4) and of various fetal malformations. Ultrasonography is the essential investigation enabling diagnosis in the presence of clinical suspicion. Surgery is obligatory, excluding any attempt in the majority of cases at extraction of the placenta, which is left in place.

[Pregnancy following female surgical sterilization. A study apropos of 38 cases]. / Grossesses survenues après stérilisation chirurgicale féminine. Etude à propos de 38 cas.

A study of 38 cases of pregnancy that occurred after sterilisation between 1st January 1981 and the 30th September 1987 at the Maternity and Neonatology Department of La Rabta, Tunis. This complication is rare because the overall global figure for failure is 7.1/1000. This is what is found in the literature. When we came to analyse the failures we found there were two groups: 15% of these failures were in women who had been sterilised correctly. This also happens when women have been sterilised with the Yonn ring as with Pomery's ligation technique. In this case when patients become pregnant there is a big chance of their being ectopic (2 tubal pregnancies as against 5 intrauterine pregnancies). 85% of failures were due to technical faults. They particularly happen with laparoscopic sterilisation (85%). They are usually due to lack of experience on the part of the operator. In any case patients do not like it; in fact 73.7% of the patients asked for a termination of the pregnancy and sterilisation was repeated in 87% of the cases.

X-ray structure analysis of 3,11,17-trioxoandrostane-5 alpha-carbonitrile and of 17 alpha-ethoxycarbonyloxy-3-oxoandrost-4-ene-17-carbonitrile.

The crystal and molecular structures of the title compounds were determined by x-ray diffractometric analysis. Torsion angles and puckering parameters are reported for both compounds. In 1 the 5 alpha-cyano group influences the A-ring conformation. The carbonate ester 3 crystallizes in the monoclinic P2(1) space group with two molecules (I and II) in the asymmetric unit. The D-ring conformation is to some extent different between I and II.

[Results at the Rabta Tunis Maternity and Neonatology Center of the surgical treatment of genital prolapse. 193 cases in 7 years (1982-1988)]. / L'expérience du Centre de Maternité et de Néonatologie de la Rabta Tunis dans le traitement chirurgical des prolapsus génitaux. A propos de 193 cas en 7 ans (1982-1988).

The authors report their experience in the treatment of 193 cases of genital prolapse treated surgically in the Rabta Tunis Maternity and Neonatology Unit during a 7 year period between January 1st 1982 and December 31st 1988. The epidemiological characteristics of the study population were dominated by the following factors: advanced age (mean age 54); multiparity (80 per cent of cases); 65.8 per cent of women were post-menopausal. The commonest association of lesions was triple prolapse, present in 78 per cent of cases. Stress incontinence of urine (SIU) was a common feature (59 per cent of cases). Treatment preference was for vaginal hysterectomy combined with anterior colporrhaphy and posterior perineorrhaphy (73.5 per cent). The Kelly Marion operation was often used for SIU (89 per cent of cases) and gave satisfactory results in 73 per cent of cases.

[Pelvic hydatid cyst and pregnancy. Four cases]. / Kyste hydatique pelvien et grossesse. A propos de 4 cas.

The association of pelvic hydatid cyst with pregnancy is rare. We collected 4 cases between 1981-1990. Our incidence is of 1/30000 deliveries. The diagnosis was suggested in 3 cases by the patient's country of origin and previous history of extra-pelvic hydatid disease. It is confirmed by ultrasonography, which is still the first choice examination. During the 3 pregnancies managed to term, we did not find any modification in the cyst. One patient had vaginal delivery twice; however complications, sometimes fatal, are reported in the literature. The time for surgery and the mode of delivery are discussed because of the rarity of this association.