A Comparative Evaluation of the Strain Transmitted through Prostheses on Implants with Two Different Macro-Structures and Connection during Insertion and Loading Phase: An In Vitro Study

Background: The purpose of this study was to measure and compare the strain levels in the peri-implant bone as generated by the blade-like implant (BLI) and the screw-type implant (STI) with two different internal connections (hexagonal and conical) and with a 1:1 and 2:1 crown/implant (C/I) ratio. Methods: The implants (BLI and STI) were placed into sawbones according to the manufacturer’s protocol. Two strain gauges, horizontal and vertical to the implant axis, were placed around each implant on the bone surface 1 mm from the cervical part. Each implant was loaded by a material testing machine at a force of 100 N. Micro-strains (με) generated in the surrounding bone were measured by a strain gauge and recorded. Results: Recorded micro-strains were not significant in both the insertion and loading phases (p < 0.0625). The average recorded micro-strain values were lower in the horizontal dimension of STI with hexagonal connection when the C/I ratio was 2:1 compared with BLI, 210 με and 443 με, respectively. Conclusion: Within the limitations of this study, implant design, implant-abutment connection and C/I ratio did not influence strain values in bone and there is no statistically significant effect of these parameters on bone.     

Serum cystatin C as an early predictor of acute kidney injury in preterm neonates with respiratory distress syndrome

Abstract

Preterm neonates with respiratory distress syndrome (RDS) are at increased risk of acute kidney injury (AKI). Our study aimed at determining whether serum cystatin C (sCysC) on day 3 of life (D3) can early predict AKI in preterm neonates with RDS. This prospective study was conducted on 75 preterm neonates; 50 with RDS and 25 without RDS. On D3, sCysC, serum creatinine (sCr) and blood urea nitrogen (BUN) were measured and estimated glomerular filtration rate (eGFR) was calculated. sCr and BUN levels were measured again on days 5 and 7. Neonates were evaluated for development of AKI during first week of life according to the modified pediatric RIFLE (pRIFLE) criteria. Thirteen neonates with RDS developed AKI (26%).There was no significant difference between RDS and control groups with respect to sCysC. RDS neonates with AKI had significantly higher sCysC than those without AKI (1.62?±?0.12 versus 1.16?±?0.09?mg/l; p?<?.001). RDS grade III–IV neonates had significantly higher sCysC than RDS grade I–II. There was a significant positive correlation between D3 sCysC and (D5 and D7 sCr and BUN). Receiver operating characteristic (ROC) curve showed that D3 sCysC can predict AKI in preterm neonates with RDS at a cutoff point of >1.3?mg/l with sensitivity of 92.30% and specificity of 96%. We conclude that neonates with RDS are at increased risk of AKI. sCysC on day 3 of life can predict AKI earlier than Cr and eGFR.     

Activity in the paracingulate and cingulate sulci during word generation: an fMRI study of functional anatomy.

The supracallosal medial frontal cortex can be divided into three functional domains: a ventral region with connections to the limbic system, an anterior dorsal region with connections to lateral prefrontal systems, and a posterior dorsal region with connections to lateral motor systems. Lesion and functional imaging studies implicate this medial frontal cortex in speech and language generation. The current functional magnetic resonance imaging (fMRI) study of word generation was designed to determine which of these three functional domains was substantially involved by mapping individual subjects' functional activity onto structural images of their left medial frontal cortex. Of 28 neurologically normal right-handed participants, 21 demonstrated a prominent paracingu- late sulcus (PCS), which lies in the anterior dorsal region with connections to lateral prefrontal systems. Activity increases for word generation centered in the PCS in 18 of these 21 cases. The posterior dorsal region also demonstrated significant activity in a majority of participants (16/28 cases). Activity rarely extended into the cingulate sulcus (CS) (3/21 cases) when there was a prominent PCS. If there was no prominent PCS, however, activity did extend into the CS (6/7 cases). In no case was activity present on the crest of the cingulate gyrus, which is heavily connected to the limbic system. Thus, current findings suggest that medial frontal activity during word generation reflects cognitive and motor rather than limbic system participation. The current study demonstrates that suitably designed fMRI studies can be used to determine the functional significance of anatomic variants in human cortex.     

Posterior reversible encephalopathy syndrome: a case following reversible cerebral vasoconstriction syndrome masquerading as subarachnoid haemorrhage

Posterior reversible encephalopathy syndrome (PRES) is a neurotoxic clinico-radiological diagnosis typically presenting with headache, encephalopathy and visual disturbance accompanied by a unique neuroradiological pattern of symmetrical parieto-occipital vasogenic oedema. Here we present the case of a 51-year-old woman who presented to hospital following a thunderclap headache, initially thought to be secondary to a subarachnoid haemorrhage (SAH). A tiny anterior choroidal artery aneurysm was demonstrated on cerebral angiogram. At surgical clipping, no evidence of haemorrhage was observed. Post-operatively, the patient developed delayed right-sided hemiparesis, managed with aggressive hypertensive treatment, and later, with onset of septicaemia, central visual loss. Computed tomography (CT) brain scans demonstrated oedematous changes within the parieto-occipital regions bilaterally and later areas of infarction. The initial diagnosis of SAH was revised to reversible cerebral vasoconstriction syndrome (RCVS), which gave rise to PRES. To our knowledge, this is the first reported case of RCVS with concomitant PRES and cerebral infarction.     

Wandering hemi-spleen: Laparoscopic management of wandering spleen in a case of polysplenia

INTRODUCTIONSeveral congenital anomalies of the spleen have been reported. The polysplenia is a rare anomaly in which the normal spleen is replaced with two or more smaller spleens. The wandering spleen is another anomaly resulting from the laxity of the splenic ligaments. The concomitance of both anomalies is very rare.PRESENTATION OF A CASEA 22-year old female patient presented with intermittent left hypochondrial pain for more than a year. After a thorough examination of the patient, she only had bilateral accessory nipples. Routine laboratory investigations were all normal. An abdominal ultrasound U/S scan was unremarkable except for a ptotic spleen. with a large splenule 5 cm × 3 cm located near the fundus of the stomach. These findings were confirmed by a CT scan. A decision for a surgical intervention was then made, and the laparoscopic approach was chosen which revealed the condition. Laparoscopic removal of the wandering part was executed. The patient discharged on the first post-operative day.DISCUSSIONThe decision making in cases of wandering spleen is not always the same. The association of a wandering spleen with polysplenia is an asset to the surgical decision, along with the age of the patient.CONCLUSIONThe laparoscopic approach is an important tool in the diagnosis and management of wandering spleen. The diagnosis of polysplenic anomaly could provide a guidance for the surgical strategy in patients with wandering spleen.     

High abundance of CD271(+) multipotential stromal cells (MSCs) in intramedullary cavities of long bones

Aspiration of iliac crest bone marrow (ICBM) remains the most frequent technique used in harvesting multipotential stromal cells (MSCs) for bone regeneration. Although this tissue type is easily accessed by a surgeon, it has a low frequency of MSCs, which is significant given the high cell numbers required for bone regeneration strategies. Lipoaspirates possess higher MSC frequencies, albeit cells with a differentiation profile less suited to orthopaedic interventions. Intra-medullary cavities of long bones have previously been shown to harbour MSCs in animals, however evaluation of their frequency, differentiation capacity and phenotype in humans had not previously been performed. Long bone fatty bone marrow (LBFBM) was collected prior to harvesting bone graft. Basic cellular compositions of donor-matched LBFBM and ICBM aspirates, including the numbers of CD34(+) hematopoietic stem cells and CD31(+) endothelial cells, were similar. MSCs were enumerated using colony-forming-unit-fibroblast assays and flow cytometry for the presence of a resident LBFBM CD45(-/low) CD271(+) MSC population and revealed a trend for higher MSC numbers (average 5 fold, n=6) per millilitre of LBFBM compared to donor-matched ICBM. Functional characteristics of resident MSCs, including their growth rates, differentiation potentials and surface phenotypes (CD73(+)CD105(+)CD90(+)) before and after culture-amplification, were similar. Enhanced numbers of MSCs could be recovered following brief enzymatic treatment of solid fragments of LBFBM. Our findings therefore reveal that the intramedullary cavity of the human femur is a depot of MSCs, which, although closely associated with fat, have a differentiation profile equivalent to ICBM. This anatomical site is frequently accessed by the orthopaedic/trauma surgeon and aspiration of the intramedullary cavity represents a 'low-tech' method of harvesting potentially large numbers of MSCs for regenerative therapies and research.     

A prognostic index (bladder prognostic index) for bilharzial-related invasive bladder cancer

PURPOSE: Bladder cancer is still the most common solid tumor among adult males in Egypt because of the prevalence of bilharzial infestation, especially in the countryside. In this prospective study, we have recorded the prognostic factors for 180 patients with invasive bladder cancer for whom standard radical cystectomy had been performed to develop a prognostic index (bladder prognostic index) that defines high risk patients who are more vulnerable to disease relapse after surgery and who may benefit from additional therapy. PATIENTS AND METHODS: The study was performed between January 1997 and December 1999, in which 180 patients with histopathologically proved invasive bladder cancer associated with bilharziasis underwent radical cystectomy or anterior pelvic exenteration. After surgery, patients were regularly followed for a minimum of 2 years. RESULTS: Our patients included 141 males and 39 females. Squamous cell carcinoma was the most common type (53.3%), and most of the tumors were grade II (61.1%). A total of 173 patients had their tumors operable, while 7 were inoperable. We had 5 (2.8%) operative related mortalities. At 5 years postoperatively, free and overall survival rates for the whole group of patients were 31.44%+/-5.9% and 32.5%+/-6.8%, respectively. Tumor pathologic stage, grade, and nodal affection were the only significant factors with impact on survival (P=0.008, 0.051, and 0.004, respectively). These 3 prognostic indexes were used to design a model to predict an individual patient's risk factor for recurrence. Patients were then assigned to one of the 4 risk groups according to the score achieved in this prognostic index (0=low risk, 1=intermediate risk, and 2 or 3=higher risk). These 4 risk groups had distinctly different rates of disease-free survival, i.e., 91.7%, 53%, 13%, and 7% for low, intermediate, and higher risk groups, respectively. CONCLUSION: Although this prognostic index appears to be of a significant clinical relevance, it needs to be more validated on a larger number of patients, and it could be a surrogate variable for biologic factors responsible for the heterogeneity of bladder cancer.     

Blunt Left Extrahepatic Bile Duct Injury: Case Report and Literature Review

Background  Extrahepatic biliary tract injuries following blunt abdominal trauma are very rare and pose a diagnostic and therapeutic challenge. Case Report  We report a case of blunt liver injury with left extrahepatic duct transection following a motor vehicle collision. Technetium 99m dimethyliminodiacetic acid scan confirmed a bile leak and endoscopic retrograde cholangiopancreatography (ERCP) diagnosed the injury of the left extrahepatic duct. Management was initially conservative, consisting of external drainage along with trials of stent placement. Ultimately, partial left hepatectomy was required to definitively treat the injury. Conclusion  In the setting of suspected biliary tract injury, early ERCP is essential to localize a leak and guide management decisions. In the event of a confirmed bile leak, a trial of nonoperative management consisting of endoscopic ductal decompression along with percutaneous drainage may initially be warranted although is not always successful.     

Evaluation of a synchronous twin-pulse technique for shock wave lithotripsy: a prospective randomized study of effectiveness and safety in comparison to standard single-pulse technique

OBJECTIVE

To asses the efficacy and safety of bidirectional synchronous twin‐pulse extracorporeal shock wave lithotripsy (ESWL) compared with standard ESWL.

PATIENTS AND METHODS

Between March 2003 and December 2006, 240 patients with a radio‐opaque single renal stone of ≤25 mm were randomized to treatment either by the Twinheads (TH) lithotripter (FMD, Lorton, Virginia, USA) or the Dornier Lithotripter S (DLS, Dornier MedTech Europe GmbH, Germering, Germany). Before and after ESWL, urinary N‐acetyl‐B‐glucosaminidase (NAG) levels were assessed and patients were evaluated with dynamic MRI. The efficacy and complications were compared, with success defined as no residual fragments.

RESULTS

For stones of >10 mm the rate for the failure of disintegration was 13.3% for the DLS vs 1.4% for the TH (P = 0.009). For stones of ≤10 mm the stone‐free rate was 74.4% for the TH vs 67.7% for the DLS (P = 0.6), while for stones of >10 mm it was 78.1% and 66.7%, respectively (P = 0.14). The median (range) number of sessions in both groups was 2 (1–5). After ESWL urinary NAG levels were increased significantly in both groups; in the TH group it declined below the level before ESWL after 2 days, while in the DLS group it remained high after 7 days. In the DLS group four patients developed subcapsular or parenchymal haematoma after ESWL, vs none in the TH group. There was loss of corticomedullary differentiation after ESWL in three patients in the DLS group and only one in the TH group. In the DLS group there was a statistically significantly decrease in bilateral renal perfusion after ESWL, but no changes in the TH group.

CONCLUSIONS

Synchronous twin‐pulse ESWL has clinical advantages over standard ESWL in terms of safety and efficacy.     

Role of Nd:YAG laser for prevention of neuroma formation: an in vivo experimental study

Nerve transection is commonly followed by the development of neuroma at the proximal stump. It can be very painful especially at exposed sites. It may arise spontaneously or after mechanical irritation. Neuroma and its high recurrence rate might be resisting problems to treat. Various treatment modalities for neuroma and its recurrence have been proposed, but none has provided satisfactory results. The present study was conducted to evaluate the neodymium:yttrium aluminum garnet (Nd:YAG) laser (1,064 nm) nerve transection technique for prevention of neuroma formation. There were 48 facial nerves out of 24 Rex rabbits divided into two equal groups. The 24 left-sided facial nerves at group A were subjected to Nd:YAG laser for nerve transection, while the 24 right-sided facial nerves at group B were subjected to scalpel nerve transection. The results were grossly and histopathologically evaluated. Grossly, laser-transected nerves showed an infrequent incidence of neuroma formation. Histopathologically, laser-transected nerves showed photothermal degenerative changes of the axons and myelin sheaths with intact perineurium and endoneurium. No Schwann cell hyperactivity could also be elicited among laser-transected nerves. Nd:YAG laser was found to be an effective tool that could be applied, whenever it is possible, for division of major nerves to prevent the formation of the subsequent stump neuroma. Moreover, this technique should be considered during treatment of well-established neuroma to prevent the challenging reported high incidence of recurrence.