How a pilot hole size affects osteosynthesis at the screw-bone interface under immediate loading.

An inappropriate pilot hole size (PHS) is one of several factors that affects the stiffness of the screw-bone fixation. The present study uses finite element models to investigate the effect of varying the PHS on the biomechanical environment of the screw-bone interface of the fractured bone, after the screw insertion and under the immediate body weight pressure (BWP). Four PHS from 71% up to 85% of the screw external diameter (SED) were considered for analysis. A non linear material behaviour of the bone with ductile damage properties was used in the study. To validate the numerical models, an experimental pull-out test was carried out using a synthetic bone. The results of the insertion process demonstrated that the relatively smaller holes (71% and 75.5% of SED) increased the insertion torque value within the recommended level, caused more bone radial extension deformation and maximized the contact area between the bone threads and the screw, in comparison to the PHS higher than 80% of SED. Under the immediate BWP after osteosynthesis, the stress level exceeds the elastic limit and becomes high enough to initiate the ductile damage of the bone. Also, enlarging PHS from 71% to 75.5% of SED increased the bone microdisplacement at the screw-bone interface from 75 up to 100 µm, and that reduced the stiffness of the fixation.

[MR imaging features of tuberculosis of the sellar region]. / Aspects IRM de la tuberculose de la région sellaire.

PURPOSE: Tuberculosis of the sellar region, especially the pituitary gland, is rare. The purpose of this article is to demonstrate through a review of five clinical cases the value of imaging, especially MR imaging, in the evaluation of this pathology. PATIENTS AND METHODS: CT and MRI of the brain were obtained in all cases along with a chest radiograph. RESULTS: Four patterns were detected on MRI: pituitary tuberculoma mimicking adenoma; pituitary abscess, extending to the cavernous sinus in one case and associated with infundibulum thickening in another; hypophysitis with suprasellar extension in association with tuberculous meningoencephalitis; and infundibular thickening associated with tuberculous meningoencephalitis. Diagnosis was based on biopsy in two cases and combination of imaging and clinical data in three cases. Outcome was favorable with anti-tuberculosis drugs. CONCLUSION: Irrespective of the imaging features, a history of travel to an endemic region combined to other findings such as infundibular thickening should raise concern for the possibility of tuberculosis even in the absence of signs of systemic infection.

Primary Plasmacytoma of the Testis with no Evidence of Multiple Myeloma: a New Case Report and Literature Review

Plasmacytomas of the testis are extremely rare tumours; especially when occurring in the absence of a previous or concurrent diagnosis of multiple myeloma. We report a new case of solitary testicular plasmacytoma; with immunohistochemical studies showing monoclonal cytoplasmic production of IgG lambda light chains; in a 51-year-old man who had no evidence of multiple myeloma 3 years after the orchiectomy

[Continent urinary diversion (Mitrofanoff principle). Physical mechanisms and urodynamic explanation of continence]. / Dérivation urinaire de Mitrofanoff. Mécanismes physiques et explication urodynamique de la continence.

OBJECTIVE: To analyze the urodynamic parameters and the mechanisms of continence of Mitrofanoff urinary diversion. MATERIAL AND METHODS: Urodynamic assessment was performed via the stoma in 11 patients with continent urinary diversion according to the Mitrofanoff principle. The mean age of the patients at the time of the operation was 29 years. The appendix, used as conduit in all cases, was anastomosed to the skin of the right iliac fossa. Ileocystoplasty was performed in 10 patients. The urodynamic assessment was performed after a mean follow-up of seven years (range: five to 12 years). RESULTS: Reservoir pressures after filling did not exceed 20 cm H2O in nine cases. Uninhibited contractions were recorded in two patients with an enlarged bladder with pressures not exceeding 30 cm H2O. Appendix pressures during filling were always higher than bladder pressures. The mean pressure measured at the end of filling was 75 cm H2O (range: 45 to 90 cm H2O). After the Valsalva maneuver, these pressures were between 80 and 150 cm H2O with good transmission. The mean conduit closing pressure was 70 cm H2O (range: 40 to 90 cm H2O). The mean functional length of the conduit was 5 cm (range: 2.6 to 7.2 cm). CONCLUSION: The Mitrofanoff diversion is mainly characterized by the high intraluminal pressure in the continent conduit. A low bladder pressure is essential to maintain a perfectly continent diversion.

Successful Treatment of Homozygous Cystinuria with Captopril

Objective : Cystinuria is an autosomal recessive hereditary disorder associated with nephrolithiasis and its attendant complications. Traditional management using oral alkali; D-penicillamine; or mercaptopropionyglycine in an attempt to increase urinary cystine solubility is often unsuccessful due to intolerable side-effects. The aim of this study was to determine; if captopril could reduce urinary cystine excretion in homozygous cystinuric patients. Patients and methods : Three cystinuric patients with a history of multiple cystine stones despite previous traditional therapy were treated with 150 mg captopril daily for 3 years after determination of their baseline 24-hour urine cystine excretion. Cystine excretion studies were repeated subsequently at 6-month intervals. Results : The baseline 24-hour urine cystine excretion was within the expected limits for homozygous cystinuria in all patients (1072; 862 and 959 mg cystine per gm creatinine per 24 hours). After institution of captopril treatment; all patients had a significant decrease in urinary cystine levels (374; 313 and 451 mg cystine per gm creatinine per 24 hours). No patient experienced recurrent nephrolithiasis or adverse drug effects. Conclusion : We conclude that captopril can significantly decrease urinary cystine excretion in patients with homozygous cystinuria. Captopril should be considered an alternative to traditional drug management of cystinuria

[Traumatic unilateral renal artery thrombosis and protein C deficiency. A case report]. / Thrombose post-traumatique de l'artère rénale et déficit en protéine C. A propos d'un cas.

Post traumatic renal artery thrombosis is rarely described in the literature. This pathology can result from stretch injury to inelastic intima of the renal artery, or by the direct flow to the abdomen causing compression injury to the renal artery against the vertebral column. However, the association of this pathology with hematologic diseases (in particular protein C deficit) was never described. We report an observation of a 28-year-old man with an uneventful history who was admitted to the intensive care unit for traumatic head injury associated with post traumatic renal artery thrombosis requiring nephrectomy. The etiologic investigation of this thrombo-embolic complication reveals a protein C deficit. Our patient was improved under treatment. This original observation confirms that post traumatic renal artery thrombosis can be associated with hematologic diseases (in particular protein C deficit).

[Feminizing testicular syndrome with multiple hamartomas and bilateral paratesticular leiomyomas]. / Syndrome du testicule féminisant associé à des hamartomes multiples et à des léiomyomes paratesticulaires bilatéraux.

INTRODUCTION: Complete androgen insensitivity syndrome or testicular feminization syndrome (TF) is the most common form of male pseudohermaphrodism, caused by a failure of androgen receptor binding. Patient with male genotype 46 XY, has a female morphotype with well developed external sexual organs. EXEGESIS: - We report the case of a 29 year-old girl with a TF syndrome discovered during the exploration of a primary amenorrhoea. Bilateral orchidectomy was performed. The testis were immature; they showed bilateral leiomyoma of the tunica albuginea and multiple hamartomas on the right side. CONCLUSION: Benign tumors are developped in 80% of cases of TF and they are generally hamartomatous nodules of testis. Association of paratesticular leiomyoma to synchronous hamartoma has never been described, its histogenesis is discussed.

[Hydatid cyst of the kidney]. / Kyste hydatique du rein.

Hydatidosis is an endemic disease caused by the larval form of Echinococcus Granulosus. Renal involvement represents less than 5% of confirmed cases. It remains clinically silent for a long time, and only presents at the stage of complications. Diagnosis is suspected on the basis of epidemiological, clinical, radiological and biological data. There are various clinical presentations. Hydaturia, which is observed in 10 to 30% of the cases, is the only pathognomonic feature. Diagnostic accuracy has been improved since the wide use of ultrasonography. Computed tomography and magnetic resonance imaging are helpful tools to confirm the diagnosis. The treatment is mainly based on surgery. The resection of the prominent dome remains the standard option as it allows preservation of the kidney. Total nephrectomy should be proposed only in case of renal destruction. The percutaneous management, which includes puncture, aspiration, injection, and reaspiration, can be performed in very selected cases. However, the results of this technique are still under debate.

Use of AMMI and linear regression models to analyze genotype-environment interaction in durum wheat.

The joint durum wheat (Triticum turgidum L var 'durum') breeding program of the International Maize and Wheat Improvement Center (CIMMYT) and the International Center for Agricultural Research in the Dry Areas (ICARDA) for the Mediterranean region employs extensive multilocation testing. Multilocation testing produces significant genotype-environment (GE) interaction that reduces the accuracy for estimating yield and selecting appropriate germ plasm. The sum of squares (SS) of GE interaction was partitioned by linear regression techniques into joint, genotypic, and environmental regressions, and by Additive Main effects and the Multiplicative Interactions (AMMI) model into five significant Interaction Principal Component Axes (IPCA). The AMMI model was more effective in partitioning the interaction SS than the linear regression technique. The SS contained in the AMMI model was 6 times higher than the SS for all three regressions. Postdictive assessment recommended the use of the first five IPCA axes, while predictive assessment AMMI1 (main effects plus IPCA1). After elimination of random variation, AMMI1 estimates for genotypic yields within sites were more precise than unadjusted means. This increased precision was equivalent to increasing the number of replications by a factor of 3.7.